Webinar Date/Time: Fri, Oct 27, 2023 11:00 AM EDT
How to enhance the sensitivity, specificity, and speed of metabolite measurement using TIMS, which in turn helps to accelerate the pace of metabolomics research.
A comprehensive monitoring protocol has been developed using GC–MS/ECD in selective ion monitoring (SIM) mode, with injection performed by solid-phase microextraction (SPME) and headspace (HS). This single system has been configured to analyze for all taste and odor (T&O) compounds in Standard Method 2170, with minimal changing of columns, injectors, or SPME fibers between methods.
When explosives are encountered on the battlefield, the use of portable GC–MS is valuable for the detection and confirmatory identification of pre- and post-detonation threats. In addition, this technique provides information about the source of explosives based on the detection and identification of trace-level chemicals in the sample. The data presented here confirm this capability.
Webinar Date/Time: Wed, Nov 15, 2023 11:00 AM EST 3:00 PM GMT | 4:00 PM BST
Examining the role that LC–MS/MS plays in metabolomics, and metabolomics’ growing importance in the field of disease biology.
Long chain fatty acids (LCFAs) function as a source of metabolic energy, substrates for membrane biogenesis, and storage of metabolic energy. Oxylipins, oxygenated derivatives of LCFAs, regulate the activity of many cellular processes. Existing methods for the analysis of LCFAs and oxylipins have limited compound coverage and sensitivity that, therefore, prevent their application in biological studies. In this work, we developed a high-throughput LC–MS method for analysis of 51 LCFAs and oxylipins. LCFAs and oxylipins were first extracted from biological samples via solid-phase extraction. The extracted molecules were analyzed by targeted comparative metabolomics. Saturated and monounsaturated LCFAs were analyzed in single ion reaction mode, while polyunsaturated LCFAs and oxylipins were analyzed in multiple reaction monitoring mode. Using this method, we successfully quantified 31 LCFAs and oxylipins from mouse livers.
Analyzing representative standard mixtures, APIs, and synthetic impurities shows that when TRLC is combined with RPLC in 2D-LC, separation performance is improved. We explain why.
A new approach based on post-column in situ hydrogenolysis, and flame ionization was used here to improve characterization of volatile aldehydes. We review and describe that approach here.
This review article discusses scientific rationales and current best practices in the pharmaceutical industry for performing chromatographic peak purity assessments (PPA). These activities are associated with the development and validation of liquid chromatographic (LC) stability-indicating analytical methods applicable to regulatory submissions of small-molecule drug candidates. The discussion includes a comprehensive overview of the PPA-related regulatory and scientific landscape and common industry approaches to obtain PPA results, as well as the strengths and weaknesses of PDA-facilitated ultraviolet (UV) PPA and other PPA techniques.
Scientists used supercritical fluid chromatography (SFC) and ultrahigh-pressure liquid chromatography (UHPLC)—both coupled with high-resolution mass spectrometry (HRMS)—to analyze various types of chlorinated paraffins (CPs) in fish oil-based dietary supplements.
HRIM has emerged as a robust separation strategy for complex chemical analyses due to its ability to improve peak capacity and aid in the separation of isobaric signals.
Untargeted GC–MS metabolomics with sample derivatization is shown here to be effective for measuring the chemical profiles of traditional and plant-based meat products.
With the advent of ambient ionization and portable mass spectrometers, the ability to perform rapid, on-site analysis is fast becoming a reality. We review the critical recent developments enabling this capability as well as remaining challenges that must be tackled to enable widespread adoption.
This month's "Directions in Discovery" gives a brief overview of turbulent- flow liquid chromatography, a technique for fast separations. Two examples demonstrate the use of the technology for high-throughput bioanalytical separations in drug discovery.
Lipid oxidation generates off-odors in food, edible oils, and fats. DHS or Thermal Extraction-GC-MS/O using Sensory Directed Analysis quickly identifies off-odors.
Quantification of European Union (EU)-priority polycyclic aromatic hydrocarbons (PAHs) in plant matrices is a crucial task. Various methods for enrichment and preconcentration, such as the preloaded-pipette tip solid‑phase extraction (SPE) (1), are available. Nevertheless, analyte recovery as a result of homogenization, sample preparation, and extraction are rarely discussed in the field of phytopharmacy. This study deals with the recovery in dry plant extracts, which are typically used in phytopharmaceuticals and reflect the actual polycyclic aromatic hydrocarbon content in the commercially available end product (2). The aim of this study was to monitor benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene loss of spiked samples as a result of commonly-used sample pretreatment, extraction, filtering, and evaporating techniques in 1:1 (v/v) cyclohexane–ethyl acetate primulae flos and sambuci flos dry extracts. Results showed that improper sample preparation can lead to false results. In the case of benzo[a]pyrene with a deviation of 155% from the theoretical true value.
Food contamination from mineral oil saturated hydrocarbons (MOSHs) and mineral oil aromatic hydrocarbons (MOAHs) is problematic and requires a sensitive analytical technique. These contaminants were analyzed using GC×GC with flame ionization detection (FID) and time-of-flight–MS (TOF–MS) parallel dual detection. The method provides enhanced chromatographic separation, along with the full mass spectra information, and overcomes difficult interferences, resulting in reduction of false positives over conventional GC–MS methods.
A fully automated quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and extract clean-up method is described for analysis of organophosphate pesticides in orange juice. This method uses GC–MS and LC–MS along with an industry standard robotic x,y,z-sampling system.
Headspace GC reveals that sonication can degrade common organic solvents.
Quantification of European Union (EU)-priority polycyclic aromatic hydrocarbons (PAHs) in plant matrices is a crucial task. Various methods for enrichment and preconcentration, such as the preloaded-pipette tip solid‑phase extraction (SPE) (1), are available. Nevertheless, analyte recovery as a result of homogenization, sample preparation, and extraction are rarely discussed in the field of phytopharmacy. This study deals with the recovery in dry plant extracts, which are typically used in phytopharmaceuticals and reflect the actual polycyclic aromatic hydrocarbon content in the commercially available end product (2). The aim of this study was to monitor benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene loss of spiked samples as a result of commonly-used sample pretreatment, extraction, filtering, and evaporating techniques in 1:1 (v/v) cyclohexane–ethyl acetate primulae flos and sambuci flos dry extracts. Results showed that improper sample preparation can lead to false results. In the case of benzo[a]pyrene with a deviation of 155% from the theoretical true value.
Overcoming the challenges of food and beverage analysis with ion chromatography (IC).
The authors developed an ion chromatography method to separate 31 cations in a single chromatographic run using inductively coupled plasma–mass spectrometry, liquid scintillation counting, and gamma counting. The high-level radioactive waste samples contained trace radionuclides in concentrations of only a few hundred disintegrations-per-minute-per-milliliter.
Online monitoring of odour and taste components that occur at parts-per-trillion (ppt) levels in industrial process waters requires specialized analytical hardware that is generally not compatible with the harsh environmental conditions in these typical industrial settings. An alternative instrumental method is proposed that uses dynamic extraction in combination with gas chromatography (GC) equipped with a simple flame ionization detector (FID) to achieve these extremely low detection limits.
Size-exclusion chromatography (SEC), with the use of ammonium acetate buffer, can be coupled on-line to electrospray ionization MS for the characterization of size variants of therapeutic monoclonal antibodies (mAbs). A quadrupole time-of-flight (QTOF) MS system was employed, and the MS method was optimized to achieve favorable sensitivity for high-mass detection, while maintaining the structural integrity of the aggregates (or high molecular weight species) and fragments (or low molecular weight species).
A GC–MS method, coupled with magnetic SPE with multi-walled carbon-nanotube (MWCNT)-coated iron oxide as the adsorbent, was developed for analyzing organophosphate esters in environmental water samples.
Compact instrumentation offers important advantages for many workflows, as illustrated by these examples.
At issue in this study was the certified value of decabromodiphenyl ether (BDE 209) in a polystyrene matrix CRM relative to its regulated value in the EU Restriction of Hazardous Substances Directive.
Matrix interferences can impact routine analysis with triple quadrupole methods for monitoring and quantifying PFAS in food.