Direct sample analysis coupled to high-resolution time-of-flight mass spectrometry (TOF-MS) may be effective at analyzing synthetic cathinones, especially for qualitative analysis, because it does not require potentially tedious sample preparation. This technique will allow for a more rapid and simplistic analysis of synthetic drugs and increase laboratory throughput, as evidenced by the work of other researchers with different instrumentation for different compound classes.

Synthetic drugs known as "bath salts," "plant food," and "jewelry cleaner" have become prominent in the United States since their introduction in 2009 (1). Products exhibit colorful packaging labels that state "not for human consumption" to allow for legal possession and recreational use by circumventing control mechanisms (2). These drugs are sold extensively via online retailers and are also carried in "head shops" and independently owned convenience stores (3). The products generally contain cathinone derivatives and produce stimulant effects similar to methamphetamine and ecstasy (4). Cathinone is a schedule I drug under the Controlled Substances Act (CSA), but it has been modified to produce a wide variety of synthetic drugs. There are dozens of known cathinone derivatives on the market and hundreds more that are possible (5). In June of 2012 the United States Congress passed the Food and Drug Administration (FDA) Safety and Innovation Act that extended the CSA to include 3,4-methylenedioxypyrovalerone (MDPV) and 4-methylmethcathinone (mephedrone) as schedule I drugs (6). 

			Synthetic cathinones are sold as tablets, capsules, and powders and have been combined with other illicit controlled substances in previous cases (7). The abuse of these drugs has also led to deaths globally (8,9).

These products can be difficult to analyze because of the possible insolubility of adulterants, cutting agents, or other added materials. Generally, analysis requires some type of sample preparation to obtain the active compounds in a suitable form, such as an organic solvent solution. Direct sample analysis time-of-flight mass spectrometry (TOF-MS) may be effective, especially for qualitative analysis, because it does not require potentially tedious sample preparation. This technique allows for a more rapid and simplistic analysis of synthetic drugs and increases laboratory throughput, as evidenced by the work of other researchers with different instrumentation for different compound classes (10,11). Analysis of such designer drugs and the identification of individual compounds may help reduce their production and abuse. 

Standard reference materials consisting of 3,4-methylenedioxypyrovalerone (MDPV), 4-methylmethcathinone (mephedrone, 4-MMC), 3,4-methylenedioxy-N-methylcathinone (methylone), butylone, naphyrone, 3-fluoromethcathinone (3-FMC), 4-methylethcathinone (4-MEC), α-pyrrolidinopentiophenone (α-PVP), 3',4'-methylenedioxy-α-pyrrolidinobutiophenone (MDPBP), 3-methyl-α-pyrrolidino-propiophenone (3-MPPP), ethcathinone, and (

]-desoxy-D2PM) were obtained from Cayman Chemical Company. Methanol (high performance liquid chromatography [HPLC]-grade) was purchased from Avantor. All solvents and chemicals used in the experiment are of a minimum purity of ACS reagent grade. 

At various times during 2011, 14 samples were purchased at a local "head shop" in State College, Pennsylvania. The bath salts included "Recharge," "White Rush," "White Girls Bath Salt," "JET Premium Bath Salts," "Ocean Burst," "Ivory Wave," and "e Blast." All of the bath salts were in powder form except for "e Blast" which was in pill form. The sample "Cosmic Blast" was labeled as a "jewelry cleaner" and was in powder form. "Doves Original," "Doves Ultra," "Exotix Super Strong," "Dynamite NRG," "Diablo's XXX Extreme," and "Space Trips Ultra" were listed as "plant food" and were all in pill form.  

 Table I:  Direct sample analysis TOF-MS instrumental conditions			

Cathinone standards were prepared by placing less than 0.5 mg of solid sample on the mesh target screen and applying 5 μL of methanol. Because of incomplete solubility in methanol of the street materials, most likely from added inactive materials, the bath salt samples were directly sampled by placing them in glass sampling tubes.  

Figure 1: Mass spectra of standard reference material MDPV using CID fragmentation (upper panel). The parent ion is 276.1595 m/z and fragments include 205.0860 m/z, 149.0235 m/z, 135.0438 m/z, and 126.1274 m/z. Fragmentation pattern of MDPV determined from its mass spectrum (lower).			

An AxION DSA TOF-MS system (PerkinElmer) was operated under the conditions listed in Table I.   

Figure 2: Mass spectrum of the reference standard 4-MEC (upper panel). The parent ion is at 192.1381 m/z and fragments include 174.1280 m/z, 145.0883 m/z, 119.0858 m/z, and 91.0563 m/z. Fragmentation pattern of 4-MEC determined by its mass spectrum (lower). The removal of water from 4-MEC is demonstrated. A double bond is formed between the carbonyl oxygen and the alpha carbon to form a hydroxyl group, which is removed to form water. Adapted from reference 12.			

Each standard was applied to the TOF-MS system's mesh target screen using 5 μL of methanol to retain the compounds. The mesh was then inserted into the system's sample tray and the standards were run as a sequence. Atmospheric positive chemical ionization (APCI) tune mix, or calibrant spray (Agilent Technologies), was run simultaneously with the standards to maintain mass accuracy. The lock mass ions used for this experiment were 

 322.0481. Standards were analyzed using both normal MS analysis for determination of the accurate masses of the parent ions, and collision-induced dissociation (CID) for fragmentation purposes. The fragment ions were chosen based on the spectral data once background ions were accounted for (Figures 1 and 2). This was performed by subtracting the APCI tune mix from each standard spectrum.  

Figure 3: Mass spectrum of "Ivory Wave" using CID fragmentation. The parent ion of MDPV (276.1596 m/z) is clearly present in the spectrum as well as fragment ions.			

Particular substituted cathinone compounds were found to exhibit the loss of water because of formation of a double bond between the carbonyl oxygen and the alpha carbon to produce a hydroxyl group. This mechanism seems to be present in straight chained cathinone derivatives (12). Specifically, this occurs with 4-MMC, methylone, 3-FMC, butylone, ethcathinone, and 4-MEC for the standards that were analyzed in this experiment (Figure 2). The loss of water was not as evident in the compounds MDPV, MDPBP, 4-MPPP, naphyrone, and α-PVP.  

Figure 4: Mass spectrum of "Ocean Burst" using CID fragmentation. The parent ion of butylone (222.1122 m/z) is clearly present. Fragment ions of butylone, ethcathinone, and 4-MEC are also indicated in the spectrum. Many of the fragment ions of ethcathinone and 4-MEC are of low intensity and are not immediately apparent. The fragment at 56.0130 m/z is most likely contributed by the sample matrix since it did not appear in the spectra of the reference standards.			

The theoretical masses of the standard reference materials were compared to the measured masses obtained using direct sample analysis TOF-MS analysis. High mass accuracy (generally less than 5 ppm error) was demonstrated for the parent ions and the majority of the fragment ions (Table II).  

Figure 5: Mass spectrum of "e Blast" using CID fragmentation. The parent ions of MDPBP (262.1436 m/z) and Î±-PVP (232.1694 m/z) are clearly present. Fragment ions of MDPBP, Î±-PVP, and 4-MEC are also indicated in the spectrum. The fragment at 56.0113 m/z is most likely contributed by the sample matrix since it did not appear in the spectra of the reference standards.			

Bath salt samples were analyzed by adding a small portion of each product to individual glass sampling tubes. The tubes were then placed in a rack suitable for the direct sample analysis interface. The reagent gas ionized and fragmented the compounds without the need for sample preparation. Approximately 10 samples were analyzed without the use of CID. The parent ions were obtained and are listed in Table III. The parent ions and fragment ions were obtained for two random single component samples (Ivory Wave, Doves Ultra) and three multicomponent samples using CID (Table III). The remaining samples were analyzed without CID. These data are also listed in Table III. Again, the instrument showed high mass accuracy even for complex mixtures. The active components in the samples were identified by comparing the parent and fragment ions of the compounds found in the sample (Table III) to those of the reference materials (Table II).  

Table II: Accurate masses of parent and fragment ions from standard reference materials			

Using direct sample analysis TOF-MS, 14 samples were screened. Parent and fragment ions for 10 different cathinone compounds were detected with excellent mass accuracy of generally less than 5 ppm. The elimination of sample preparation makes analysis easier especially when tedious extraction methods or derivatization otherwise are used (13). This also significantly increases the number of samples that can be screened in a given time. Some current methods that use gas chromatography–mass spectrometry (GC–MS) can take up to 30 min to analyze one sample while the direct sample analysis TOF-MS approach enables the analysis of one sample in 15 s. The use of this approach could, therefore, significantly increase laboratory throughput for qualitative identification. The drawback with direct sample analysis TOF-MS, however, is that quantification of the active compounds cannot be performed. Additionally a library of standard reference materials is needed to identify the cathinones, which can be expensive or commercially unavailable. It is also difficult to identify particular isomers using this technique because of a lack of retention time data.  

Table III: Accurate masses of parent and fragment ions of compounds detected in bath salt samples			

Synthetic cathinones can be easily analyzed using direct sample analysis TOF-MS. Direct sample analysis TOF-MS has been shown to be an efficient analytical tool in the analysis of bath salt samples and can potentially replace current techniques to improve laboratory productivity. A similar approach may also be useful for additional compound classes where similar needs exist.  

 is an associate professor at The Pennsylvania State University in University Park, Pennsylvania. 

is with the forensic science program at The Pennsylvania State University. 

are with Perkin Elmer Corporation in Shelton, Connecticut. Direct correspondence to: 

(1) European Monitoring Centre for Drugs and Drug Addiction. Advisory Council on the Misuse of Drugs: Consideration of the Cathinones.  

http://www.emcdda.europa.eu/publications/drug-profiles/synthetic-cathinones

(5) National Alliance for Model State Drug Laws. Cathinone Derivatives Trade Name and Chemical Compound Chart. 

http://www.namsdl.org/documents/CathinoneDerivativesTradeNameandChemicalCompoundChart.pdf

(6) S. 3187:Food and Drug Administration Safety and Innovation Act. 112th Congress, 2011-2012. Passed June 27, 2012. 

(7) Drug Enforcement Administration. Request for Information on Synthetic Cathinones.  Microgram Bulletin. [Online] 2011, 44(4), 31-37. 

http://www.justice.gov/dea/programs/forensicsci/microgram/mg2011/mg0411.pdf

Articles

Direct sample analysis coupled to high-resolution time-of-flight mass spectrometry (TOF-MS) may be effective at analyzing synthetic cathinones, especially for qualitative analysis, because it does not require potentially tedious sample preparation.

Analyzing Synthetic Cathinones Using Direct Sample Analysis Time-of-Flight Mass Spectrometry

Military jet fuel (JP-8) is very similar to commercial jet fuel (Jet A) except for the presence of three additives, fuel system icing inhibitor, corrosion inhibitor–lubricity improver (CI-LI), and antistatic additive, which are added to improve characteristics of JP-8. Of particular interest is the CI-LI additive; the most common active ingredient is a dimer of linoleic acid. This article focuses on quantification of the active ingredient in the CI-LI additive by liquid chromatography–mass spectrometry (LC–MS). This method will allow the determination of CI-LI content in military jet fuel samples.

Aviation fuels consist primarily of a complex mixture of linear, branched, and cyclic hydrocarbons (C

) (1), aromatic carbons (2) with trace amounts of polar impurities. The polar impurities are important because their reactivity has a dramatic effect on the formation of deposits in the fuel (3). Military aviation fuels (JP-8) are supplemented by a series of additives including fuel system icing inhibitor (FSII), antistatic additive (static dissipator additive, or SDA), and corrosion inhibitor–lubricity improver (CI-LI) (4). The first two of the additives are easily analyzed by gas chromatography (GC) or other experimental methods, but the CI-LI additive is too high in molecular weight for GC. The only documented method for its determination is a complex method involving a combination of extraction and gel permeation chromatography (GPC) (5).  

The typical active ingredient in several CI-LI additives is a dimer of linoleic acid. The dimer is usually prepared by the clay catalyzed dimerization of linoleic acid, which results in the formation of a mixture of acyclic, monocyclic, and bicyclic compounds (6). The reaction also results in a variable number of remaining double bonds (7,8) providing compounds with molecular weights ranging from 556 to 564 amu. The dimer of linoleic acid has found wide applicability in a range of commercial products, including cosmetics and industrial lubricants (9). It has been shown to reduce corrosion (10) and improve the lubricity (11) of crude and refined oils. In military aviation fuels, it is added to reduce the wear in roller bearings in the fuel pumps and also reduce corrosion in the fuel system tubing. Given its important function in the fuel system, analysis of fuels for their CI-LI content has become more important.   

High performance liquid chromatography (HPLC) has been an important tool for the analysis and characterization of fuel samples (12). The method has been shown to group components conveniently into nonpolar and polar components. However, it does not provide an analysis of the specific contaminants in the sample. Liquid chromatography–electrospray ionization mass spectrometry (LC–ESI-MS) has been used in the analysis of specific polar components in fuels (13). Electrospray ionization is especially convenient as a soft ionization method that does not ionize the nonpolar components of the fuel sample (14). The negative ion mode is particularly useful, because of the common polar impurities only the phenols appear as negative ions under normal conditions. The dimer acid ionizes efficiently in negative ion mode. In addition, the high molecular weight of the dimer acid also separates it from the common phenols found in fuels. 

In this study, we describe a simple method for the determination of CI-LI in aviation fuels using HPLC with ESI-MS detection. The method requires no sample preparation beyond dilution in methanol, provides a reproducible linear calibration curve, and suffers from few interferences. The method is demonstrated for the analysis of CI-LI in a series of fuel samples. 

Samples of eight different CI-LI additives approved for use in JP-8 fuels and several fuel samples containing CI-LI additives were supplied by the Fuels branch at Wright Patterson Air Force Base in Dayton, Ohio. 

Figure 1: Total ion chromatogram for a typical aviation fuel sample.			

The HPLC–ESI-MS system used for the current study was an Agilent 1200 series liquid chromatograph with an Agilent 6210 time-of-flight (TOF) mass spectrometer and an Agilent G3251A electrospray source. An Agilent C8, 2.1 mm i.d., 5-µm particle size, 100-Å pore size column was used for this study. The column was temperature controlled at 30 °C to create a consistent, slightly above ambient temperature condition improving the repeatability of the chromatographic separation. The electrospray source was operated at a capillary voltage of 3500 V, using an 11-L/min flow of nitrogen at a temperature of 325 °C as the drying gas. The nebulizer pressure was 50 psi and the fragmentor voltage was set to 200 V. Before reaching the TOF system, the sample loop was run through a diode-array detector to measure the UV absorbance at 254 nm. The mobile phase consisted of methanol (Fisher Scientific Optima LC–MS grade), with 0.1 vol% acetic acid added. The elution was carried out isocratically for all samples at a flow rate of 0.30 mL/min. 

Figure 2: Total ion chromatogram and the selected ion chromatograms for several components of the CI-LI additive.			

The HPLC chromatograms of fuel samples containing the CI-LI additive show a single major peak at a retention time of 0.9 min with a very weak broad feature at 1.2–2.3 min (Figure 1). The majority of the polar components are contained in the sharp peak at 0.9 min; however, the CI-LI additive appears in the broad later peak. The principal components observed in negative ion mode are phenols and carboxylic acids that form negative ions by losing a hydrogen ion in electrospray ionization (15). 

Figure 3: Compounds formed from the dimerization of linoleic acid with clay catalysis: (a) acyclic, (b) monocyclic, and (c) bicyclic dilinoleic acid structures. The structures may contain additional double bonds.			

To identify the main component in the CI-LI additive, the LC–MS chromatogram of all of the commercial additives was examined. The total ion chromatogram (TIC) shows a sharp peak at 0.9 min with a broad peak at 1.2–2.3 min. The peak at 0.9 min is because of polar components in the additive carrier. The broad feature between 1.2 and 2.3 min is because of the dilinoleic acid components in the additive. The TIC and extracted ion chromatograms (EIC) for various components are shown in Figure 2. The width of the second peak is consistent with the CI-LI additive being composed of a mixture of the monocyclic and bicyclic compounds with differing numbers of residual double bonds (Figure 3). 

Figure 4: The mass spectrum of a CI-LI additive (top) and an expansion of the region around 560 amu (bottom).			

The mass spectrum shows a cluster of peaks separated by 2 mass units centered on mass 561 amu (Figure 4). The high-resolution mass spectrum gives a mass consistent with the structures shown in Figure 2. The measured mass, actual mass, formula, and possible structures are shown in Table I. 

Figure 5: Calibration curves for the determination of CI-LI additive in a fuel sample.			

To determine the amount of additive in fuel samples, a calibration curve was prepared by measuring several known concentrations of the CI-LI active ingredient dissolved in HPLC grade methanol. The area of the MS signal at 562.496 ± 0.004 amu was used for the determination. To ensure reproducibility of the measured calibration curve, a second set of samples was prepared and analyzed the next day. The calibration curves are shown in Figure 5. The calibration curve was found to be linear over a wide range of concentrations. The curves for the two days are nearly identical and the correlation coefficient of 0.99 indicates a good linear relationship. Similar calibration curves prepared for other masses found in the mass spectrum of the additive give similar results. 

Table I: Molecular weights, structures (Figure 3) for the components of dilinoleic acid in CI-LI additives			

The linear calibration curve allows the quantification of the CI-LI indicator to be achieved in a series of fuel samples. Based on the noise in the various samples and the noise in the blank, the detection limit for CI-LI in a fuel matrix is estimated at 0.2 mg/L. Based on a specification for JP-8 of 9–24 mg/L of the CI-LI additive in the fuel samples (4), the method allows for accurate quantitation of the additive in jet fuel samples. The analytical results for a series of seven different aviation fuel samples is shown in Table II. Each of the six JP-8 samples shows an appropriate CI-LI additive concentration, although many of the samples are near the lower end of the specified range. 

Table II: CI-LI determination for several jet fuel samples (sample A is not formulated to include CI-LI and is included for reference)			

The use of high performance liquid chromatography with time-of-flight mass spectrometry detection for the determination of dilinoleic acid as a corrosion inhibitor and lubricity increasing additive shows good linearity and day-to-day reproducibility. The high resolution of time-of-flight mass spectrometry ensures that other possible components of the fuel do not interfere significantly with the determination of the active component of the additive. The analysis is complicated by the complex nature of petroleum-based fuels and the distribution of molecular weights and structures associated with the available dilinoleic acid–based additives. For aircraft fuels without sample preparation beyond dilution with methanol, the detection limit is 0.3 mg/L. If solid-phase extraction techniques are used in sample preparation, a significantly lower detection limit is achievable. 

This material is based on research sponsored by the Air Force Research Laboratory under agreement number FA8650-10-2-2934. The United States government is authorized to reproduce and distribute reprints for governmental purposes notwithstanding any copyright notation therein. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the Air Force Research Laboratory or the United States Government. 

 is with the Department of Chemistry at the University of Dayton in Dayton, Ohio. 

 is with the Wright Patterson Air Force Base, AFRL/RQTF, in Dayton, Ohio. 

 is with the University of Dayton Research Institute. Direct correspondence to: 

(1) R. van der Westhuizen, M. Ajam, P. De Coning, J. Beens, A. de Villiers, and P. Sandra, 

(2) C.G. Fraga, B.J. Prazen, and R.E. Synovec, 

(3) R.C. Striebich, J. Conteras, L.M. Balster, Z. West, L.M. Shafer, and S. Zabarnick, 

(4) M. LePera, JETAl vs JP-8 Differenced and Effects on Long Term Use. 7 June 1999. 

www.guartermaster.army.millpwd/papers/jet-alvsjpS.pdf

(5) B.H. Black, M.A. Wechter, and D.R. Hardy, 

(6) R.F. Paschke, J.E. Jackson, and D.H. Wheeler, 

(7) D.H. Wheeler, A. Milun, and F. Linn, 

(8) R.F. Paschke, L.E. Peterson, and D.H. Wheeler, 

Preprints of Papers - American Chemical Society, Division of Fuel Chemistry 

(10) P.W. Fischer, U.S. Patent 2805201, Sept. 3, 1957. 

(11) R. Caprotti, B.W. Davies, and B. Dilworth, U.S. Patent 5833722, 1998. 

(12) L. Balster, S. Zabarnick, R.C. Striebich, L.M. Shafer, and Z.J. West, 

(13) R.K. Adams, S. Zabarnick, Z.J. West, R.C. Streibich, and D.W. Johnson, 

(15) K. Qian, W.K. Robbins, C.A. Hughey, H.J. Cooper, R.P. Rodgers, and A.G. Marshall, 

Military jet fuel (JP-8) is very similar to commercial jet fuel (Jet A) except for the presence of three additives, fuel system icing inhibitor, corrosion inhibitor–lubricity improver (CI-LI), and antistatic additive, which are added to improve characteristics of JP-8.

Determination of Corrosion Inhibitor–Lubricity Improver in Jet Fuels by Liquid Chromatography–Electrospray Ionization Mass Spectrometry

Simple, sensitive, rapid, selective, and precise reversed-phase liquid chromatography (LC), electrospray ionization mass spectrometry (ESI-MS), and tandem MS (ESI-MS-MS) methods were developed and validated for the determination of 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) in bovine serum and sea water matrix. HMTBA is the α-hydroxy analog of the sulfur-containing amino acid methionine and is extensively used as a methionine supplement in poultry and bovine feed. 

Methods were developed and validated for the determination of 2-hydroxy-4-(methylthio)butanoic acid (HMTBA), which is a water-soluble hydroxy acid. HMTBA is a commercially available α-hydroxy analogue of the sulfur-containing limiting amino acid methionine.  

HMTBA and its isopropyl ester has been shown to be a highly effective dietary methionine supplement in dairy cows, poultry, and aquaculture (1–10). It has been shown that both the D and L enantiomers are converted to L-methionine (L-Met) through a stereospecific transamination pathway (11–13). The relative efficacy of uptake of racemic HMTBA and D,L-Met have been investigated in several studies; efficacies in such studies have been established through growth rate assessment in poultry or milk production rate in lactating cows. Studies show that HMTBA or its isopropyl ester supplementation yield higher growth rates and higher milk yields than Met supplementation (13,14). Uptake of HMTBA and its subsequent conversion to methionine has been studied in lactating dairy cows with infusion of 

C-labeled HMTBA. It was shown that infusion of HMTBA increased whole-body plasma flux of Met (15). It has been postulated that uptake of Met and HMTBA from the gastrointestinal track involve different mechanisms; Met uptake involves an active transport across the cell membrane and HMTBA uptake occurs through diffusion, this uptake is more efficient especially when animals experience stress, for example, heat stress. It has also been shown that HMTBA can lead to increased production of antioxidant metabolites such as taurine and reduced glutathione (16). However, experiments that link HMTBA supplemented in feed directly with its concentration in blood serum have not been reported in literature.  

HMTBA has also been used in a chelated form such as zinc-HMTBA (Zn-[HMTBA]

) which is an efficient carrier of micronutrients (17,18). Zinc-HMTBA chelate has also been used as an antifouling agent in marine paints and coatings (19). It has been reported that it minimizes biofouling and is less toxic to the environment than other Zn and tin-based antifouling agents. It has also been shown that Zn-HMTBA is more effectively retained in the coatings. However, direct leaching of HMTBA from marine coatings and its stability in the marine environment have not been reported because of a lack of accurate and precise methods for HMTBA determination in sea water. This article deals with a sensitive, accurate, and precise method for quantification of HMTBA in blood serum and sea water.  

HMTBA was obtained from Novus International, Inc. High performance liquid chromatography (HPLC)-grade acetonitrile, methanol, and acetone were obtained from Fisher Scientific. Ammonium hydroxide (NH

OH, 28–30% solution of ammonia in water) and sodium chloride (NaCl, certified ACS grade) were also obtained from Fisher Scientific. Trifluoroacetic acid (spectrophotometric grade) was procured from Sigma-Aldrich. Adult bovine serum was obtained from Hyclone. Water was purified with a Synergy 185 filtration system (Millipore) prior to use. Mobile phases were filtered using 0.22-μm type GV membrane filters (Millipore) before use. Sample solutions were filtered through 0.1-μm type GVHP membrane filters (Millipore) before the analysis. Bovine serum and sea water samples were obtained from Novus International, Inc. All the samples were stored at -30 °C before the analysis. 

HMTBA determinations were carried out using a Hitachi LaChrom Elite HPLC system (Hitachi High Technologies America) equipped with a model L2100 solvent delivery system, a model L2200 autosampler, a model L2300 column oven, and a model L2450 diode array detector. 

HMTBA determinations were also carried out with a Varian (Agilent Technologies) model 1200 L triple-quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source and a Harvard 11 plus infusion syringe pump. The liquid chromatography–tandem mass spectrometry (LC–MS-MS) system consisted of Prostar 210 solvent delivery pumps, a model Prostar 410 autosampler, and a model Prostar 325 dual-wavelength UV–vis detector (all from Agilent Technologies).  

Accurate mass measurements of selected samples were carried out with a Varian 920 FT-MS ion cyclotron resonance system equipped with a 7-T magnet and Omega FT-MS workstation version 9.2.30 software.  

Serum samples (1 mL) were stored at -30 °C; samples were transferred and then lyophilized for 12 h. The lyophilized residue was mixed with 2 mL of methanol, agitated with a vortex mixer for 30 s, and then sonicated for 5 min. The sonicated mixture was centrifuged for 15 min at 3000 rpm, supernatant was transferred to a 10-mL vial. The precipitate was extracted twice with 2 mL of methanol. The extracts were pooled and brought to near dryness under a nitrogen stream. The dried residue was reconstituted in 1 mL of a 50:50 (v/v) water–methanol mixture. Sample extracts were filtered through 0.1-μm syringe filters and an aliquot was introduced into either a reversed-phase LC, ESI-MS, or ESI-MS-MS system for HMTBA determination. 

Sea water samples were extracted with a procedure similar to that used for the extraction of serum samples. Sea water samples (1 mL) were stored at -30 °C, and samples were transferred and then lyophilized for 12 h. The lyophilized residue was mixed with 2 mL of acetone and agitated with a vortex mixer for 30 s, then sonicated for 5 min. The sonicated mixture was centrifuged for 15 min at 3000 rpm, and the supernatant was transferred to a 5-mL vial. The precipitate was extracted twice with 2 mL of acetone. The extracts were pooled and brought to near dryness under a nitrogen stream. The dried residue was reconstituted in 1 mL of a 50:50 (v/v) water–methanol mixture. Sample extract aliquots were filtered through 0.1-μm syringe filters and 5-μL aliquots of the filtered extracts were introduced into either a reversed-phase LC, ESI-MS, or ESI-MS-MS system for HMTBA determination. 

Separation of HMTBA from coextractants present in the samples was achieved with a 25 cm × 4.6 mm, 5-μm 

 C18 column. The mobile phase consisted of water and acetonitrile with 0.1% trifluoroacetic acid. Both the isocratic and the gradient elution were evaluated. The isocratic elution was carried out with 20:80 (v/v) water–acetonitrile with 0.1% trifluoroacetic acid. In gradient elution, the mobile phase composition was changed from 100% water (0.1% trifluoroacetic acid) to 70% water and 30% acetonitrile (0.1% trifluoroacetic acid) in 15 min. The mobile-phase flow rate during both the isocratic elution and gradient elution was maintained at 1 mL/min. The separated components were detected with a diode-array detector over the 190–350 nm wavelength range. 

The mass spectrometer was operated with an ESI source in the negative ion mode. Ions produced in the ESI source were monitored both in the scan and selected ion monitoring (SIM). During the scan mode, the mass range was set between 100 and 150 amu. During SIM only one ion, 

 149, was monitored. The ion source temperature was set at 50 °C, the needle voltage was maintained -3500 V, the ion capillary shield voltage was set at -600 V, the capillary voltage was set -80 V, and the detector voltage was set at +1600 V. Air was used as the nebulizing gas, and its pressure was set at 50 psi. Nitrogen was used as the drying gas, and its pressure was set at 18 psi; the drying gas temperature was set at 150 °C. A 50:50 water–methanol mixture was used as the carrier solvent in the direct infusion pump, and its flow rate was set at 100 μL/min.  

 149 was selected as the precursor ion in Q1; the ion energy was set at 15 eV. Argon was used as the collision gas in Q2, and collision-induced dissociation (CID) fragment ions were monitored with Q3 over the 

 50–149 range. The principal fragment ion was found to be 

 101. In a later experiment, Q3 was set in SIM at 

HMTBA Quantification in Bovine Serum and Sea Water Samples 

Two sets of calibration standards were prepared by fortifying aliquots of bovine serum (free of HMTBA) and simulated sea water with an HMTBA stock solution in methanol. The simulated sea water was prepared by dissolving 4.0% sodium chloride in deionized water. The HMTBA concentration in the calibration standards for HPLC ranged from 1.0 to 100.0 μg/mL, while the concentration range for ESI-MS and ESI-MS-MS was 0.001–10 μg/mL. The HMTBA in the fortified aliquots was extracted with the extraction procedure was outlined in a previous section.  

Limit of Detection and Limit of Quantification 

The limit of detection (LOD) and limit of quantification (LOQ) in the present context refer to the lowest concentration of HMTBA in bovine serum and 4% salt solution that can be detected and unambiguously quantified. The LOD was a concentration that yielded a signal-to-noise ratio (S/N) of 5 and the LOQ was a concentration that yielded a S/N of 10. Both parameters were evaluated by monitoring signal from six replicate aliquots. The precision was assessed in terms of percent relative standard deviation (% RSD) for the response factors.  

Figure 1: Chemical structures of HMTBA and methionine. 			

The linearity of the reversed-phase LC, ESI-MS, and ESI-MS-MS methods was determined with five-point calibration curves, and the linearity was evaluated in terms of correlation coefficient (

Figure 2: Molecular structure of zinc-HMTBA chelate (Zn[HMTBA]2). 			

The accuracy of the methods is determined with bovine serum and 4% salt solution samples fortified with known concentrations of HMTBA. Accuracy of the methods was also assessed through quantification of HMTBA in "blind" check samples that were obtained from Novus International.  

Figure 3: Chromatograms of unfortified simulated sea water (top) and a simulated sea water sample fortified with HMTBA (bottom).			

Sample Preparation  and HMTBA quantification 

Isocratic and Gradient Elution Reversed-Phase LC

Liquid–liquid and solid–liquid extraction were evaluated and optimized. The aim of optimization was to minimize interference, ion suppression, and extraction period and maximize analyte recovery. The liquid–liquid extraction involved addition of an organic solvent directly to the bovine serum or simulated sea water samples. For solid–liquid extraction, the serum and simulated sea water samples were first lyophilized and the solid residue was then extracted with an organic solvent. The extracts were introduced into reversed-phase LC, ESI-MS, and ESI-MS-MS systems for HMTBA quantification.  

Figure 4: Chromatograms of unfortified (top trace) bovine serum extract and fortified bovine serum extract (bottom trace) obtained with isocratic elution. 			

Quantification of HMTBA in sea water and bovine serum extracts was first carried out on the reversed-phase LC system, where HMTBA eluted from the C18 column was quantified by monitoring absorbance at 210 nm. A rapid isocratic elution with 50:50 (v/v) water–methanol mixture as the mobile phase with a flow rate of 1 mL/min was first evaluated, and the elution time for HMTBA under these conditions was found to be 5.1 ± 0.02 min. Figure 3 shows the chromatographic outputs for unfortified simulated sea water sample and simulated sea water sample fortified with HMTBA.  

Figure 5: Chromatograms of unfortified bovine serum extract and fortified bovine serum extract obtained with gradient elution. 			

Figure 4 shows the isocratic chromatographic analyses of the methanol extracts of unfortified bovine serum sample and bovine serum sample fortified with HMTBA. Chromatograms show the presence of peaks that can interfere with HMTBA, making quantification at concentrations below 10 μg/mL very difficult.  

Figure 6: Negative ion ESI-MS spectrum of HMTBA mass scan range m/z 50â150.			

The matrix interferences observed in bovine serum samples under isocratic elution method were eliminated with gradient elution using the reversed-phase LC method. The gradient elution parameters were selected to keep retention factor (

') for HMTBA less than five and the total run time of 15 min with complete elimination of potential interfering coeluted compounds. Chromatographic profiles obtained with gradient elution of unfortified bovine serum sample and serum sample fortified with HMTBA at 10 μg/mL are shown in Figure 5. The LOQ for HMTBA in serum sample with methanol denaturation–extraction followed by the gradient elution reversed-phase LC and quantification at 210 nm was found to be 0.5 μg/mL.  

Figure 7: Equilibrium equation for HMTBA in sea water. 			

ESI-MS — Negative Ion Selected Ion Monitoring 

Deprotonation of HMTBA results in the pseudomolecular anion 

 149, which can be readily monitored with ESI-MS operating in the negative ion mode. The negative ion ESI-MS spectrum of HMTBA is shown in Figure 6. The spectrum shows the presence of only one dominant peak at 

 149. With selected ion monitoring, the LOQ for HMTBA in organic- and salt-free basified water–methanol solutions was found to be 1.0 ng/mL.  

Simple, sensitive, rapid, selective, and precise reversed-phase liquid chromatography (LC), electrospray ionization mass spectrometry (ESI-MS), and tandem MS (ESI-MS-MS) methods were developed and validated for the determination of 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) in bovine serum and sea water matrix. HMTBA is the ?-hydroxy analog of the sulfur-containing amino acid methionine and is extensively used as a methionine supplement in poultry and bovine feed.

Determination of 2-Hydroxy-4-(methylthio)butanoic Acid in Bovine Serum and Sea Water

Canola largely contains unsaturated fatty acids, thus rendering it clear in most cases after extraction and refining. However, canola can become cloudy even at room temperature. The cloudiness is thought to be largely because of the presence of wax esters transferred to the oil from the plant tissues during extraction and increased saturated fatty acid content. Methods have previously used saponification to measure the fatty alcohol and fatty acid components of the wax esters. Others have used solid-phase extraction with gas chromatograph      y–mass spectrometry. This study shows that high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC–QTOF-MS) can directly analyze the wax esters with a simple filter sample preparation step. Using HPLC–QTOF-MS also allows for direct analysis of other fatty components in the sample such as triacylglycerols.

Canola oil is predominately composed of unsaturated fatty acids, thus rendering it clear in most cases after extraction and refining. However, there are instances in which canola can become cloudy even at room temperature. Cloudy canola oil is not typical for the consumer and, therefore, has a negative connotation. 

 is a process in which solids in an oil can be removed, but this added processing step can be costly. Typically, canola oil does not require dewaxing, which, in addition to the low amount of saturated fatty acids, makes it a desirable option for salad oils. Industrially, a cold test is used to see if the oil will become hazy upon storage (1). The oil is heated to 130 °C and then immersed in an ice water bath maintained at 0 °C for 5.5 h. The sample is examined for any evidence of crystals or cloudiness. The sample must be completely clear to pass the test. A lack of clarity indicates the potential for the oil to become hazy over time. 

The cloudiness sometimes observed in canola and other oils is thought to be mainly because of the presence of wax esters (2–5) transferred to the oil from the plant tissues and increased levels of saturated fatty acids (2). The increased wax esters can arise in different growing seasons because of varying environmental conditions. Wax esters are made up of a fatty acid and fatty alcohol. These components tend to be long carbon chains 20–28 carbons in length. They can be saturated or unsaturated, although saturated chains are reported more often (2–4). Waxes can act as an organogelator in liquid oils. An organogelator must have a balance of insolubility and solubility in the solution (6). Liquid oils and waxes can have such a relationship. The gelling of waxes with liquid oils has been studied.  Sunflower wax esters have been shown to be able to create an organogel in soybean oil at a concentration of 0.5% (7).   

Methods have previously used saponification to measure the fatty alcohol and fatty acid components of the wax esters (2). Other studies have used solid-phase extraction with silica gel and gas chromatography–mass spectrometry (GC–MS) (8) as well as silver nitrate–impregnated silica gel with liquid chromatography (LC) (9) to characterize the wax ester fractions of olive and sunflower oils. Studies that have not used a mass spectrometer for detection characterize the composition of the waxes by their number of carbons and degree of unsaturation (8,9). This type of analysis is also common for analyzing triacylglycerols. However, there can be different isomers of each wax. Therefore, mass spectrometry is needed to fully elucidate the composition of each type of wax ester. This study confirms that high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC–QTOF-MS) can directly detect the wax esters with a simple sample filtration preparation step. HPLC–QTOF-MS also allows for direct analysis of other fatty components in the sample such as triacylglycerols. 

Canola oil with visible cloudiness at room temperature was filtered through a Buchner funnel fitted with black filter paper for visual confirmation of collection of white material. Material on the filter paper was scraped off and collected for analysis. Approximately 10 mg of the collected material was diluted in 25 mL of 80:20 methylene chloride–acetonitrile. 

Standards were purchased from NuChek Prep and included lignoceryl lignocerate, behenyl behenate, behenyl oleate, arachidyl oleate, stearyl oleate, and stearyl linoleate. Approximately 1 mg of standard was diluted in 25 mL of 80:20 methylene chloride–acetonitrile. 

The collected material was analyzed on an Agilent 1290 HPLC system coupled to an Agilent 6520 QTOF-MS system with an electrospray ionization (ESI) source. Mobile-phase A consisted of 80:20 water–2-propanol and mobile-phase B was 80:10:10 butanol–water–2-propanol, each with 25 µM ammonium formate added. The mobile phase was ramped from 30% B to 100% B over a period of 24 min at 0.25 mL/min. A 100 mm × 3.0 mm, 2.7-µm 

 Agilent Poroshell 120 EC-C18 column was used and held at 50 °C. The ESI was used in positive mode with the nebulizer set at 30 psig. The drying gas was heated to 325 °C and introduced at a flow rate of 4 L/min. Full-scan data were acquired by scanning from 

 1500. Targeted MS-MS was done on the waxes using a mass-dependent formula with a slope of three and 

-intercept of 10 for the collision energy. 

Compounds were found using the molecular feature extractor in Agilent's Quant MassHunter software. The composition of known wax esters were added into the personal compound database library (PCDL) which can then be searched using the MassHunter software. MS-MS analysis was necessary to positively identify each wax ester. 

 are esters with varying chain lengths of alcohol and fatty acids. Therefore, there are different isomers possible and MS-MS analysis breaks the ester linkage, thereby allowing the identification of the alcohol and fatty acid components. 

 Table I: Formula information for wax standards			

The mass spectra obtained from the wax standards show that the predominant ion is the ammonium adduct of the ester.  Table I summarizes the masses and adducts formed. A previous study on quantitating positional isomers of triglycerides showed that the ammonium adducts had the least amount of in-source fragmentation (10). Many lipids require the use of adducts to ionize, and other adducts such as lithium, sodium, or silver were shown to have increased diacylglycerol fragments. This principle was used here as well and was helpful for quantitation. The [M+H]

  ion was also present for the standards, but was quite small in comparison to the ammonium adduct.  

Figure 1: MS and MS-MS spectra of lignoceryl lignocerate. The prevalent ion is the ammonium adduct in the MS spectrum and the [M+H]+ fragment of lignoceric acid in the MS-MS spectrum.			

MS-MS analysis of the standards shows an interesting fragmentation pattern depending on the chain length and unsaturation of the fatty acids and alcohols present in the wax. Lignoceryl lignocerate and behenyl behenate have fragments that are the [M+H]

  of the fatty acid. Lignoceryl lignocerate is made up of a C

 fatty acid and alcohol. The fragment present for lignoceryl lignocerate is the [M+H]

  of lignoceric acid (Figure 1). Behenyl behenate is made up of a C

 fatty acid and alcohol. The fragment present for behenyl behenate is the [M+H]

  of behenic acid (Figure 2). The MS-MS spectra of behenyl oleate has the [M+H]

  of the behenic acid, but also has representative fragments for the oleate moiety. In Figure 3, the fragments at 

 111.1186 and 125.1339 represent the fragmentation of oleic acid at the C9 carbon and subsequent CH

 loss.  Arachidyl oleate, stearyl oleate, and stearyl linoleate have very similar fragmentation patterns. There is no fragment for the saturated component, but there are fragments representing the unsaturated component. The fragments present represent the unsaturated portion with subsequent losses of oxygen and hydrogen. Arachidyl oleate and stearyl oleate have a very similar fragmentation pattern (Figures 4 and 5). The ions at 

 247.245 and 265.256 represent the oleate component and losses of oxygen. There is also a small fragment at 

  fragment corresponding to oleic acid. There is a cluster of fragments from 

 107–209 that show subsequent losses of CH

. This may arise from fragmentation of the saturated component of the wax. A similar pattern is seen for arachidyl oleate, stearyl oleate, and stearyl linoleate. Stearyl linoleate differs from arachidyl oleate and stearyl oleate in the fragments at 

245.2298 and 263.2405 (Figure 6). These fragments are from linoleate and subsequent losses of oxygen and hydrogen. It is a similar pattern to the waxes containing oleate. 

Figure 2: MS and MS-MS spectra of behenyl behenate. The prevalent ion is the ammonium adduct in the MS spectrum and the [M+H]+ fragment of behenic acid in the MS-MS spectrum.			

An interesting point is that the unsaturated portion of the analyte appears to stay intact rather than fragmenting when the wax contains an unsaturated chain and a saturated chain of 20 carbons or less. This is also seen in the fragmentation patterns for triacylglycerols. Data from Malone and Evans (11) show that fragmentation increases with increasing degree of unsaturation. This was speculated to be because ammonium ion affinity is likely to be greater with increasing unsaturation. This pattern also seems to be applied to the waxes when both saturated and unsaturated chains are present. The unsaturated component of the ester may be preferentially ammoniated, and therefore is not fragmented. The saturated component is then fragmented and showing subsequent losses of CH

 (Figures 4–6). Behenyl oleate does not behave in this way, however. Instead of the main fragments coming from oleate, the fragment is the [M+H]

  ion from behenic acid (Figure 3). One explanation is that ammonium ion affinity may also increase with chain length. If this is the case, going from 20 carbons to 22 carbons may be a tipping point for the preference of the ammonium adduct formation in the wax esters. This, in combination with the waxes containing two saturated components, also shows that the fragmentation pattern of the saturated components do not always include the CH

Figure 3: MS and MS-MS spectra of behenyl oleate. The prevalent ion is the ammonium adduct in the MS spectrum and the [M+H]+ fragment of behenic acid in the MS-MS spectrum. The MS-MS spectrum also has fragments at m/z 111.1186 and 125.1339 that represent the fragmentation of oleic acid. 			

The main components of the filtered material found in this analysis are ammonium adducts of triglycerides typical of canola oil. In the triglycerides present, there was no indication of larger amounts of saturated fatty acid containing triglycerides such as tristearin. This is contrary to other reports (2), which attributed the cloudy material not only to waxes, but also to saturated fatty acid containing triglycerides. The large amount of liquid oil in the filtered material was confirmed by viewing the sample under a microscope. The microscope shows a crystal network of solid and liquid material, indicating that the wax esters identified in the sample can trap liquid oil within its crystal network during crystal formation. This crystal network with trapped liquid oil is what causes the oil to become hazy or cloudy in appearance (Figure 7). 

Figure 4: MS and MS-MS spectra of arachidyl oleate. The prevalent ion is the ammonium adduct in the MS spectrum and the [M+H]+ and oxygen loss fragments of oleic acid in the MS-MS spectrum.  			

MS analysis showed wax esters with a range of 44–54 carbons to be present. In this range, the C

 wax ester has the largest peak area. In addition to the even-numbered wax esters present, smaller quantities of esters containing odd numbers of carbons are also present. Like the standards, the most abundant ion represents the ammonium adducts. The [M+H]

  ion was also present in lesser abundance. The range of wax esters found is typical for plant materials (2–4). 

Figure 5: MS and MS-MS spectra of stearyl oleate. The prevalent ion is the ammonium adduct in the MS spectrum and the [M+H]+ and oxygen loss fragments of oleic acid in the MS-MS spectrum.  			

In addition to the ability to positively confirm the compounds present, using mass spectrometry as a detection method can help to deconvolute coeluted compounds. There can be overlapping of the waxes with a similar number of carbons and unsaturation, but the software can separate the compounds with different masses and similar retention times. 

Figure 6: MS and MS-MS spectra of stearyl linoleate. The prevalent ion is the ammonium adduct in the MS spectrum and the [M+H]+ and oxygen loss fragments of linoleic acid in the MS-MS spectrum.  			

MS-MS analysis showed that the esters contained carbon chain lengths of 20–28. The nature of the analytes makes it difficult for complete elucidation of each wax component. For instance, the C

were greater in abundance, indicating that, in this case, the wax tends to be more asymmetric rather than having components of the same chain length on each side of the ester linkage. In other reports in which the waxes were separated into their alcohol and acid components before GC analysis, the fatty alcohol tended to have longer chain lengths than the fatty acid (4). This would correlate to the work done here in that the chain lengths would appear to be asymmetric. This method could also be applied to other oils that exhibit cloudiness. 

Figure 7: Micrograph of the filtered solids. The dark areas represent pockets of oil that are trapped within the wax and fat crystal network.			

LC–QTOF-MS has been shown to provide a direct analysis for the solid material that causes cloudiness in canola oil. In the case of the cloudy canola oil studied here, verification of waxes in the cloudy material was possible via filtration of the oil, dilution of the collected material, and analysis by LC–QTOF-MS. There are many different isomers possible for the wax esters. MS-MS was used to elucidate the composition of the wax esters present. Many waxes are available commercially as standards and can be added into a user library for compound confirmation. This method can also be used for other oils that contain waxes of similar compositions.  

Susan Seegers, Gabriela, Sekosan, and Tiffanie West

 are with Bunge North America in Bradley, Illinois.

 Official Method Cc 11-53 (American Oil Chemists' Society [AOCS], Urbana, Illinois).			

(3) R. Przybylski, C.G. Biliaderis, and N.A.M. Eskin, 

(4) P. Kolodziejczyk "#91-08, Identification of Waxes in Canola Oil," available at: 

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.199.2019&rep=rep1&type=pdf

(5) H. Liu, R. Przybylski, K. Dawson, N.A.M. Eskin, and C.G. Biliaderis, 

(6) H.S. Hwang, S. Kim, M. Singh, J.K. Winkler-Moser, and S.X. Liu, 

(10) L.C. Herrera, M.A. Potvin, and J.E. Melanson, 

Canola largely contains unsaturated fatty acids, thus rendering it clear in most cases after extraction and refining.

LC–MS Identification of Wax Esters in Cloudy Canola Oil

The 62nd Conference on Mass Spectrometry and Allied Topics (ASMS) took place this year June 15–19, at the Baltimore Convention Center in Baltimore, Maryland. Preceding the conference program opening, one- and two-day short courses took place on Saturday, June 14 and Sunday, June 15. 

The conference program opened Sunday with tutorial lectures and a plenary lecture followed by a welcome reception in the poster and exhibit hall. The tutorials were given by Lucinda Cohen of Merck Research Laboratories (Whitehouse Station, New Jersey), and Ron M.A. Heeren of FOM Institute AMOLF (Amsterdam, Netherlands). Cohen's talk was titled "Mass Spectrometry in the Pharmaceutical Industry: Everything You Ever Wanted to Know but Were Afraid to Ask." Heeren's talk was titled "Imaging Mass Spectrometry." 

ASMS Vice President for Programs Jenny Brodbelt, of the University of Texas, Austin, then officially welcomed conference-goers. She was followed by Jason Kalirai of the Telescope Science Institute (Baltimore, Maryland) whose talk was titled "The James Webb Space Telescope: From First Light to the Search for Earth 2.0." 

Three more plenary events took place during the week. The Monday and Tuesday plenary sessions were award lectures given by Richard M. Caprioli and Lingjun Li (details below). On Thursday, Erez Lieberman Aiden of Baylor College of Medicine and Rice University (Houston, Texas) spoke on "How the Genome Folds." Following the course of previous years, the conference also featured daily oral sessions, poster sessions, exhibits, and workshops. 

Oral sessions, poster sessions, and exhibits took place throughout the day, Monday through Wednesday, and workshops took place throughout the day, Monday through Thursday. 

A small exhibit featuring models of spaceflight mass spectrometers used in the exploration of the solar system over the past several decades was displayed in the Convention Center's Pratt Lobby. Models on display included engineering units, flight spares, and demonstration reproductions from the robotic planetary missions to Venus, Jupiter, Saturn, Titan, and Mars. Experts were on hand to answer questions about instrument design, mission science achievements, and future directions associated with the instruments. 

Several awards were presented at this year's conference. The Award for a Distinguished Contribution in Mass Spectrometry was presented on Monday afternoon to Richard M. Caprioli of Vanderbilt University (Nashville, Tennessee) for the development of matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry and its application to molecular mapping of tissues in biology and medicine. Caprioli's work led to a new paradigm for molecular imaging of tissues, founded on the development of MALDI imaging mass spectrometry. This is now a burgeoning application of mass spectrometry whereby molecular measurements can be made directly from tissues, adding significantly to the information that can be obtained from these specimens. 

The Biemann Medal went to Lingjun Li of the University of Wisconsin-Madison (Madison, Wisconsin) for the number and depth of her contributions in the field of mass spectrometric study of neuropeptides and functional peptidomics. Li's research program is focused on the development of novel and improved mass spectrometry (MS)-based tools in conjunction with microseparation techniques to study challenging neuroscience problems including functional discovery of neuropeptides and biomarker discovery in neurodegenerative diseases. Li and her team have created several multifaceted and integrated MS-based platforms that include high resolution in-situ peptide mapping, tissue imaging, in vivo microdialysis, high sensitivity microseparation techniques coupled with tandem MS 

 sequencing, and new isotopic and isobaric labeling strategies, and improved bioinformatics tools to allow large-scale discover and functional analysis of novel neuropeptides.  

Research awards in the amount of $35,000 each, funded by Thermo Scientific and Waters Corporation, were presented to Kerri A. Pratt of the University of Michigan (Ann Arbor, Michigan), and Zhibo Yang, of the University of Oklahoma (Norman, Oklahoma). 

ASMS inaugurated the Post-Doctoral Awards this year, presenting three awards of $10,000 each to promote the professional career development of postdoctoral fellows in the field of mass spectrometry. Activities envisioned for this award include, but are not limited to, conference and workshop attendance, travel to other mass spectrometry laboratories, and purchases of books and software. The awards are open to ASMS members who are postdoctoral fellows within three years of completing a PhD or equivalent degree. This year's recipients were Huilin Li of the University of California, Los Angeles, Boone Prentice of Vanderbilt University, and Hao Zhang of Washington University at St. Louis. 

The Ron A. Hites Award for an Outstanding Research Publication in the 

Journal of the American Society for Mass Spectrometry (JASMS)

 went to Evan Williams and coauthors Harry J. Sterling, Alexander F. Kintzer, Geoffrey K. Feld, Catherine A. Cassou, and Bryan A. Krantz for their paper "Supercharging Protein Complexes from Aqueous Solution Disrupts their Native Conformations." The award is named in honor of Professor Ron Hites of Indiana University, who led the creation of 

 in 1988 while president of ASMS. The corresponding author receives a cash award of $2000 and authors are acknowledged with certificates of commendation. 

A closing event took place at the National Aquarium, located along Baltimore's Inner Harbor. The aquarium was closed to the general public during the event, and, along with hors d'oeuvres and drinks, attendees were treated to an iMax film, a dolphin event, and music provided by several of their colleagues. 

The 63rd Annual ASMS Conference will be held May 31–June 4, 2015, in St. Louis, Missouri. For more information, visit 

We present a brief review of this year's ASMS conference, which took place June 14–19, 2014, in Baltimore, Maryland

Special Issues-07-01-2014 | LCGC Supplements

Analyzing Synthetic Cathinones Using Direct Sample Analysis Time-of-Flight Mass Spectrometry

Determination of Corrosion Inhibitor–Lubricity Improver in Jet Fuels by Liquid Chromatography–Electrospray Ionization Mass Spectrometry

Determination of 2-Hydroxy-4-(methylthio)butanoic Acid in Bovine Serum and Sea Water

LC–MS Identification of Wax Esters in Cloudy Canola Oil

ASMS Review

Vol 12 No 3 Current Trends in Mass Spectrometry July 2014 Issue PDF