Cannabinoids are successfully extracted from a complex brownie matrix using the QuEChERS sample preparation technique, significantly reducing the presence of matrix interferences. The resulting clean samples are analyzed by GC–MS using a specialized deactivated GC column to provide heightened peaks for the cannabinoid compounds.
This article describes possible sources of error that may contribute to significant inaccuracy in peptide assay methods: The fi ltration material (cellulose) used in sample clean up and the vial material (glass and plastic) used in LC analysis. This study is based on ?-endorphin but has relevance for most peptide assays.
Sample pretreatment is often a time consuming and labor-intensive step which can be a restricting factor for the rapid analysis. This is especially true for the analysis of drugs in biofluids containing many interfering matrices.
Ionization of small, large, volatile, and nonvolatile compounds with charge states nearly identical to electrospray ionization are produced from a solid matrix or solution with high sensitivity utilizing the vacuum inherent with any mass spectrometer. With the proper matrix, analytes can be analyzed from ambient conditions or by direct introduction into vacuum.
Analysis of OCPs, PAHs and PCBs in environmental samples through a consolidated GC-MS/MS method using the Thermo Scientific™ TRACE™ 1310 GC and the TSQ™ 8000 triple quadrupole GC-MS/MS.
A snapshot of key trends and developments in the chromatography sector according to selected panelists from companies exhibiting at Analytica 2018.
SFC–GCxGC is shown to be useful in fossil fuel analysis. Practical examples for the analysis of complex matrices are described.
A method is presented for the determination of ?-amanitin, a toxic cyclic octapeptide of amanitin mushrooms, in human serum by solid-phase extraction coupled with high performance liquid chromatography with UV detection.
Sample pretreatment is often a time consuming and labor-intensive step which can be a restricting factor for the rapid analysis. This is especially true for the analysis of drugs in biofluids containing many interfering matrices.
Note discusses how labs are coping with the worldwide helium shortage.
The quantitative performance of the latest generation of high-resolution instruments is comparable to that of a triple quadrupole MS, even though different scanning modes are used. Higher-resolution instrumentation also allows flexibility concerning compound identification because the experiment can be set up for targeted quantitation, screening, or both. In an Orbitrap-based instrument, the parallel reaction monitoring (PRM) mode performs most closely to a triple quadrupole mass analyzer using selected reaction monitoring (SRM) mode. This study looks at the performance of an Orbitrap-based LC–MS method for EPA Method 539.
Chiral chromatography has become the preferred tool for enantiomer separations in the early stages of pharmaceutical development for the purpose of accurately identifying single pure enantiomers with pharmacologic, toxicological, and clinical information, as stipulated by the FDA.1
Analytical methods are developed at various stages of the drug develoment process for samples of varying complexity.
Professor Boguslaw Buszewski, Chairman of ISC 2012 and President of EuSSS, CeGSS and the Polish Chemical Society, reveals the highlights of last year's illuminating programme.
Published methods for the determination of ibuprofen in biological fluids by liquid chromatography (LC)–UV or LC–mass spectrometry (MS)-MS have quantitation ranges consistent with the relatively high but typical ibuprofen dose (200–800 mg), generally having lower limits of quantitation in the low micrograms-per-milliliter range. For the analysis of plasma and synovial fluid samples from preclinical (miniature swine) studies utilizing a novel ibuprofen dosage form, LC–MS-MS methods were developed and validated over the 10–1000 ng/mL range. Ibuprofen undergoes biotransformation to ibuprofen acyl glucuronide and sublimes under routine bioanalytical sample handling conditions. Procedures were implemented to minimize the impact of these potential liabilities.
The majority of the samples in this study and other studies show that a majority of compounds can be separated by the use of the three most common alcohols: IPA, CH3OH, and ethanol. Solubility becomes a crucial factor in preparative chromatography. Combinations of solvents can be used to improve solubility when the chosen co-solvent has poor solubility of the compound in question.
A newly discovered method, matrix-assisted ionization (MAI), is described for generating gas-phase ions from volatile and nonvolatile compounds. The method is both simple and sensitive.
A high performance thin-layer chromatographic (HPTLC) method was developed for the determination of aflatoxin B1 in cereals.
The identification of nontargeted species in environmental and commercial samples by mass spectrometry can be very difficult. In this article, authors from Eastman Chemical Company describe their systematic approach for the identification of nontargeted species using nominal and accurate mass data, searching both mass spectral and "spectra-less" databases.
Recent advances in sampling techniques in the pharmaceutical industry sparked significant interest in applying improvements to extraction methods for greater analyte detection and quantitation.
High performance liquid chromatography (HPLC) with light absorbance detection (UV) is limited by the dependence of detector response on the structure of the analyte. Some detection techniques based on nebulization of the mobile phase and formation of Aerosol particles demonstrate an analyte independent response that approaches "universal."
Native mass spectrometry, the method by which noncovalent protein complexes are retained in the gas phase for intact mass analysis, is gaining interest as a method for intact protein characterization. The development of a modified orbital ion trap platform for high-resolution analyses has expanded the role of native mass spectrometry to address the challenges of intact protein characterization.
Carotenoids are a class of natural pigments, widely distributed in vegetables and fruits. A comprehensive two-dimensional liquid chromatography (LC×LC) method, based on the use of a cyano and an octodecylsilica column, placed in the first and second dimension, respectively, was applied to evaluate carotenoid composition and stability in selected overripe fruits representing the waste generated by a local food market. This research also evaluates if post-climacteric biochemical changes are linked to carotenoid degradation in the investigated fruits. A total of 22 compounds was separated into seven different chemical classes in the two-dimensional space, and identified by photodiode array (PDA) and mass spectrometry (MS) detection. The results prove that the waste generated by the large distribution of food still represent an important source of bioactives that could be used for other purposes.
It is hypothesized that in particular cases, conventional planar chromatography provides a more effective and robust system than column chromatography with regard to separation efficiency and peak distribution of mixtures composed of low-retarded analytes. Under similar reversed-phase experimental conditions, a regular distribution of thin-layer chromatography (TLC) spots of four natural estrogens (estetrol, estriol, 17?-estradiol, and estrone) corresponds to strong irregular dispersion of peaks in chromatograms generated by high performance liquid chromatography. In both cases, the efficiency of separation was assessed using simple optimization criteria such as selectivity (?min) and resolution (Rs min). The distribution of chromatographic spots was evaluated using the relative resolution product (r). The results revealed that an excellent separation of the components of interest could be achieved easily using simple nonforced and isocratic TLC. Such an interesting property of planar chromatography is mainly driven by the nonlinear relationship between k and Rf retention factors. This article also reports the practical advantages of TLC for the separation of estrogenic steroid mixtures at different temperatures.
How to use small columns to test potential biphasic liquid systems for use in large-scale countercurrent chromatography separations
Using a targeted solid phase extraction (SPE) method and GC–ECD analysis, chlorinated pesticides are extracted from poultry fat resulting in a method that decreases the amount of labor and reagents when compared to the USDA-FSIS CHC2 method.
A fast and simple sample preparation method for the simultaneous determination of 11 phytohormones in plants by GC–MS has been developed.