PerkinElmer Inc., Waltham, Massachusetts, USA.

Phthalates are added to plastics to increase flexibility. Recently, concerns have been raised over the effect of phthalate exposure from plastic materials on human health. This health concern has resulted in regulations regarding the type and levels of phthalates allowed in toys. Gas chromatography–mass spectrometry (GC–MS) is an excellent instrumental platform for the identification and quantification of phthalates in plastic-toy components. This paper will demonstrate a GC–MS calibration for common phthalates and the analysis of plastic-toy components for phthalate content. 

The PerkinElmer Clarus 600 GC–MS system provided the instrumental platform for this analysis. The GC was fitted with a programmable split/splitless injector; the injector-port temperature was maintained at 280 °C. The injector-port liner was packed with glass wool to improve vaporization and provide a surface for the collection of any dissolved plastic. A PerkinElmer Elite-5ms (30 m × 0.25 mm × 0.25 μm) GC column was temperature programmed from 100 °C to 260 °C at 8 °C/min, then to 320 °C at 35 °C/min. The carrier gas, helium, was set to 1 mL/min with 25 mL/min split at the injector port. Phthalate calibration standards were prepared in methylene chloride across a range of 1 and 160 μg/mL; the calibration standards used contain 16 phthalates. 

An unused toy was broken into small pieces; 1 g samples were taken from each of the 9 different types of plastics used in the toy.  The samples were extracted through 15 minutes of sonication in 10 mL of methylene chloride, in a sealed vial. Following extraction, 1 mL of the sample extract was transferred into an autosampler vial for analysis; a 1 μL injection was made. 

The instrument calibration across the range of 1 to 160 μg/mL for each phthalate was linear with R

  greater than 0.999 for all compounds. Applying the calibration range to a 1 g sample extracted in 10 mL of solvent relates a % weight calibration range of 0.001 to 0.16% weight phthalate in the sample. 

The analysis of the toy samples resulted in detection of phthalates in each of the different plastic materials; however, the phthalate level of all analyses was well below the regulatory limits. A sample analysis is pictured in Figure 1. In the chromatogram, three peaks are evident: butylated hydroxytoluene, diisobutyl phthalate and din-butyl phthalate. Butylated hydroxytoluene is an antioxidant commonly added to polymers. The total % weight of phthalates in this component was 0.007%. 

European and North American countries have set limits on the acceptable levels of phthalates in toys. As a result, a reliable technique to determine the phthalate level in toys is necessary. The GC–MS technique presented here will allow for the determination of the phthalate content in plastic-toy components. 

940 Winter Street, Waltham, Massachusetts 02451 USA 

Articles

General

Phthalates are added to plastics to increase flexibility. Recently, concerns have been raised over the effect of phthalate exposure from plastic materials on human health.

GC–MS Determination of Phthalate Concentration in Plastic Toys

 Thermo Fisher Scientific, San Jose, California, USA, 

 Thermo Fisher Scientific, Shanghai, China, 

 Shanghai R&D, Nu Sin Enterprises, Shanghai, China. 

Type 2 diabetes is the most common metabolic disease worldwide. Although the prevention and control of it remains unclear, there is strong evidence that dietary factors play a role in the onset of this disease. Previous studies have indicated that cinnamon may mimic insulin effects and thus may improve glucose uptake.

In this application, profiling and structural elucidation of polyphenol polymers, the possible active compounds in cinnamon, are performed using an LC–MS

  methodology using the LCQ Fleet ion trap mass spectrometer. 

An aliquot (0.5 g) of cinnamon was ground and extracted in 8 mL 0.1 N acetic acid using a sonic bath for 3 minutes. The supernatant liquid was cooled to room temperature and diluted in mobile phase. The final solution was filtered prior to HPLC separation. LC separation was performed using a C18 column and detected at 280 nm wavelength. Sample fractions CB4 with insulin enhancing activity were collected, and the powders were dissolved in water:MeOH:ACN 25:50:25 solvent for LC–MS

A range of procyanidins from cinnamon extract fractions have been identified and characterized within a rapid ten-scan-event LC–MS

  analysis [Figure 1(a)]. The fast positive/negative switching the capability of the LCQ Fleet mass spectrometer ensured comprehensive structural information for compounds ionized in both positive and negative mode was collected in a single chromatographic analysis. Figure 1(b) and Figure 1(c) demonstrated the MS

 ) data of one trimer procyanidin in both positive [Figure 1(b)] and negative [Figure 1(c)] polarities from fraction CB4. The ability to perform MS

  analysis on precursor ions (isolated using HRI) using the ion trap enables the structural elucidation of these compounds with less interference from the matrices. The presence of 

 289 in negative MS–MS spectrum is considered to be specific for a C-O-C IFL in the polymers.

  method has been developed to characterize the various procyanidin oligomers in the Chinese cinnamon extract. Both A-type and B-type polymers were found. The fast cycle time and excellent MS

  capability of the LCQ Fleet enabled the confident identification of the components of interest. 

3. S.M. Lampke et al., Poster on Experimental Biology, (2006). 

5. S. Guyot, J. Vercauteren and V. Cheynier, 

355 River Oaks Parkway, San Jose, California 95134-1991, USA 

tel. +1 800 532 4752  fax +1 561 688 8731 

Medical/Biological

Profiling and Characterization of Polyphenol Polymers from Cinnamon Using an Ion Trap Mass Spectrometer

Tosoh Bioscience GmbH, Stuttgart, Germany,
	

	Water soluble cationic polymers can be designed with performance profiles for a broad range of different application fields. They are used in detergents and cleaners, as coagulants and flocculating agents in the paper industry and wastewater purification as well as in many technical applications. Another application field is the cosmetics industry, where cationic polymers are used in hair shampoos as conditioning agents.

	Cationic polymers based on ethyleneimine (PEI) exhibit a strong and permanent binding to surfaces, they are exceptional adhesives. As a result they can be used in a variety of applications such as coatings, as primers for polymer compounds in film formation and for surface modification in dyeing of plastics. Polyallylamine (PAA) and other polyamine copolymers are used in the coating of textiles to prevent colour fading.

 Cationic dextranes, polyethyleneimines and polylysines are used for transfection of cells or for drug delivery because they form complexes with nucleic acids like DNA or siRNA.

 The behaviour and efficiency of cationic polymers for a certain application is based upon the size and characteristics of the individual polymer.

	SEC combined with multi-angle laser light scattering (MALLS), refractive index or viscometric detection is a common means for the characterization of polymers. The challenge in SEC analysis of cationic polymers is the potential interaction of the highly adhesive polymers with the column packing. This impairs peak shape and molecular weight determination.

 With most SEC columns the undesired interactions are suppressed by using a mobile phase with a high salt content, bearing the risk of precipitation and low recovery.

	A new type of SEC column was developed to overcome the need of high salt eluents in SEC determination of water-soluble cationic polymers. TSK-GEL PWXL-CP columns are based on the well known PW-type of polymeric resins for aqueous SEC. The surface of the polymethacrylate base material was modified by incorporating a cationic functionality. This modification results in high recovery of cationic polymers and enables elution under low salt conditions. The columns show high theoretical plate numbers, linear calibration curves and high durability. They are produced with three different pore sizes resulting in different separation ranges.

Low Salt SEC Analyis with TSK-GEL PWXL-CP Columns

The high reproducibility of SEC separations of cationic polymers on TSK-GEL PWXL-CP columns was demonstrated by repeated injection of a high molecular weight polyallylamine (PAA). PAA (MW 438000) was injected onto a TSKgel G5000PWXL-CP column and analysed at 25 °C using a mobile phase containing 0.1 M NaNO3. Figure 1 shows the high reproducibility of the SEC analysis without any adsorption of the polymer. The recoveries of the PAA polymer were measured as well. High recoveries of more than 97% were obtained with all three types of TSK-GEL PWXL-CP columns.

The analysis of different low molecular weight polymers of allylamine (PAA) and ethyleneimine (PEI) can be performed by combining two of the TSKgel G3000PWXL-CP columns in series (Figure 2). The TSKgel G3000PWXL-CP column has the smallest pore size in the series of SEC columns for cationic polymers. The use of two columns in series provides a very good separation of the three PEI polymers with molecular weights of 3000, 8000 and 21000 respectively. PEI is of special interest as a powerful non viral gene-transfection agent, which condenses nucleic acids by ionic interactions.

	Figure 3 shows the elution profiles of a variety of cationic polymers with different functional groups. For this application the three types of TSK-GEL PWXL-CP were connected in series. The polymers elute in the expected order of their molecular weight demonstrating that there was no influence of the type of functional group. There was no ionic interaction observed which was interfering with the size exclusion mode.

The data presented in this application note shows that the new type of SEC columns can be used for the analysis of a variety of aqueous cationic polymers. The recoveries of the cationic polymers were excellent on each grade of the new columns, thus demonstrating that these columns will be valuable to both QC and polymer research laboratories. They provide an improved tool for researchers in the different application fields of cationic polymers ranging from applied chemistry to drug delivery and genetic engineering.


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	64347 Griesheim
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Analysis of Cationic Polymers by Size Exclusion Chromatography (SEC)

ESPCI, Laboratoire Environnement et Chimie Analytique, 10 rue Vauquelin, Paris, France, 

SGE EUROPE, 12 avenue du Québec, Courtaboeuf, France, 

SGE Analytical Science, 7 Argent Place, Ringwood, Victoria, Australia. 

The detailed molecular characterization of feedstocks and resulting products is a critical issue to better understand and improve hydroconversion processes.

  Neutral (indole, carbazole) and basic (aniline, quinoline and acridine) nitrogen containing hydrocarbons present in middle distillates at concentrations as low as 0.1–2.0% w/w poison catalysts used for hydrodesulphurization (HDS).

  They are also refractory to hydrotreatment processes preventing the efficient upgrade of middle distillates to transportation fuels.

  Conventional molecular analysis techniques fail to provide a detailed characterization of nitrogen compounds. As investigated here, comprehensive two-dimensional gas chromatography (GC×GC) appears to be a promising technique for overcoming these limitations. 

A diesel cut was provided by IFP-Lyon, from cokefaction (diesel B, density: 0.880; total N: 1328 ppm; total basic N: 501 ppm; bp: 200–423 °C). A synthetic mixture of 14 relevant N-compounds (N-Mix) obtained from Chiron (Villeurbanne, France), Sigma-Aldrich (Lyon, France) and Acros (Noisy le grand, France) was prepared for GC×GC separation evaluation. 

Several secondary columns have been investigated for the separation of some reference nitrogen compounds occurring in middle distillates.

  Results are presented in Figure 1 and demonstrate that the combination of a polar and longer SolgelWax as the second dimension column to a first non polar BPX5 column allows the total separation when hyphenated. 

Diesel B was then analysed using this column combination. The resulting GC×GC chromatogram is shown in Figure 2. 

The results clearly show that GC×GC allows the comprehensive separation and precise quantitative analysis of nitrogen compounds by chemical class in middle distillates. 

The enhanced peak capacity and sensitivity of comprehensive two-dimensional gas chromatography provided unequalled separation and identification of nitrogen compounds in diesel samples. 

The proposed GC×GC method allows the accurate determination of basic to neutral nitrogen ratio. For the first time, the comprehensive determination of nitrogen compounds by family can also be reported. 

7 Argent Place, Ringwood, Victoria 3134, Australia 

tel. +61 3 9837 4200  fax +61 3 9874 5672 

The Application Notebook-03-01-2008

GC–MS Determination of Phthalate Concentration in Plastic Toys

Profiling and Characterization of Polyphenol Polymers from Cinnamon Using an Ion Trap Mass Spectrometer

Analysis of Cationic Polymers by Size Exclusion Chromatography (SEC)

Comprehensive 2D GC for Achieving Nitrogen Speciation in Middle Distillates