Author
Latest:
Analysis of 17-Pesticide Residues in Apple Using Agilent SampliQ QuEChERS EN Kits and Agilent J&W Ultra Inert columns by GC–MSThe QuEChERS method for pesticide analysis was first introduced by USDA scientists in 2003. The EN method 15662:2007 is a European variation to the QuEChERS method. The method uses acetonitrile extraction, followed by the salting out of water from the sample using anhydrous magnesium sulphate (MgSO4, NaCl and buffering citrate salts to induce liquid–liquid partitioning.
Latest:
Real-Time Response to Bacteria Infection of Bioethanol Fermentation Using a Short Rezex™ ROA ColumnPolitical priorities as well as economic interests have fueled a dramatic growth in the biofuel industry, due much in part to research funding and tax incentives. Currently the world's ethanol production is estimated to be over 16 billion gallons a year. This number is expected to increase in the next few years, reaching an estimated yearly production of 20 billion gallons by 2012. Today, many ethanol producers add fermentors to expand their production capacity. In order to continue using existing HPLC equipment for the increased monitoring, increased analytical throughput is needed.
Latest:
From Academician to Entrepreneur — A Convoluted TrekWalt Jennings briefly sketches a path, occasionally humorous, occasionally somber, from the time of his Ph.D. candidacy in 1953 to the present day.
Latest:
Headspace Analysis of Volatile Organic Compounds (VOCs) in Contact Packaging Materials Using the HT3 Automated Headspace AnalyzerThe United States Food and Drug Administration (U.S. FDA) and the European Union (EU) have published regulations and provided guidance on the use of chemicals in food packaging materials. Tekmar provides method parameters for the HT3â„¢ Automated Headspace Analyzer for the determination of VOCs that may be contained in food contact packaging materials under various conditions. Temperature and mixing parameters were investigated to determine which VOCs may be released when subjected to these conditions.
Latest:
Recent Advances in Ultrahigh-Pressure Liquid ChromatographyUltrahigh-pressure liquid chromatography (UHPLC) is a technique that is experiencing continued growth due to the benefits in separation power and speed of analysis over traditional HPLC. We attempt here to give an overview of some of the advances that have occurred in UHPLC since 2003, from the standpoint of both fundamental research and the introduction of commercially-available technology.
Latest:
Quantitative Analysis of Pseudoephedrine Tablets by UHPLC–MSAn effective UHPLC–MS method for high throughput separation, identification and quantification of pseudoephedrine was developed on a Hypersil GOLD PFP 1.9 µm, 2.1 Ã- 100 mm column.
Latest:
Comparison of Quadrupole, Time-of-Flight, and Fourier Transform Mass Analyzers for LC-MS ApplicationsThe authors investigated the analytical capabilities of quadrupole, time-of-flight, and Fourier transform mass analyzers for liquid chromatography electrospray mass spectrometry (LC-MS) applications.
Latest:
A Comparison of ICP-OES and ICP-MS for the Determination of Metals in FoodThe determination of inorganic elements in food substances is critical for assessing nutritional composition and identifying food contamination sources. The inorganic elements of interest can be divided into two classes: nutritional and toxic. It is important to determine the levels of both sets of elements accurately to assess both the nutritional and the harmful impacts of food substances. Nutritional elements such as Mg, P, and Fe are present at high levels (milligrams per kilogram), while toxic elements such as Pb, Hg, and Cd should be present only at trace levels (nanograms or micrograms per kilogram).
Latest:
The Integration of Microextraction Packed Sorbent (MEPS) into Multidimensional StrategiesLC/GC approaches to analysis are attractive because they combine the selectivity of solid-phase sorbents in the first dimension with the separating power and peak capacity of capillary GC in the following dimensions.
Latest:
Quantitative Analysis of PFAS in Milk, Infant Formula, and Related Ingredients Using LC–MSThis method for PFAS analysis in milk and infant formula is robust, reliable, and reproducible, with scope to expand the list of PFAS in the future.
Latest:
The Benefit of Headspace Trap Coupled with GC–MS for the Determination of Trace Levels of BTEX Compounds in Drinking WaterThis article will focus on the development of an optimized gas chromatography–mass spectrometry (GC–MS) method that improves upon the current EPA and European detection limit requirements for BTEX compounds and meets all other criteria described in EPA Method 524.2 for the measurement of purgeable organic compounds in water by capillary column GC–MS.
Latest:
Quantitation and Confirmation of the Pesticide Malathion in Fruit Samples using Multiple ReactionMonitoring and MS-MS-MSLC–MS-MS instruments operating in Multiple Reaction Monitoring (MRM) are widely used for targeted quantitation on triple quadrupole and hybrid triple quadrupole linear ion trap (QTRAP® ) systems because of their well known selectivity and sensitivity. In MRM mode, the first quadrupole (Q1) filters a specific precursor ion; the collision cell (Q2) generates fragments (product ions) which are filtered in the third quadrupole (Q3). Although this double mass filtering greatly reduces noise there is always a chance that elevated background levels or matrix signals interfere with the targeted analyte.
Latest:
Free Excel Software for Performing Virtual Liquid ChromatographyA new free simulator is available for students, educators, and trainers to teach and perform virtual HPLC experiments that are applicable to real HPLC instrumentation and method development.
Latest:
Rapid Sampling and Identification of Volatile and Semivolatile Organic Compounds by GC-TMS in Support of Decision Quality DataAs analytical chemist(s), the data collected from samples we test represent information. That information may be required to direct environmental clean-up operations, help insure worker safety, or guide decisions for an emergency response to a chemical incident.
Latest:
A Robust and Sensitive Method for Detecting Glyphosate and Other Polar Pesticides in Food and Water: Multiple Analytes in a Single Injection without DerivatizationA new high-throughput LC–MS/MS method meets the challenge of eliminating matrix effects for monitoring, with high specificity, polar organic pesticides such as glyphosate in food and water, while meeting targeted limits of detection.
Latest:
Planar Chromatography — Back to the Future?Planar chromatography celebrates its 70th birthday. The technique dates back to 1938 when, at the Pharmaceutical Institute in Kharkov, Ukraine, N.A. Izmailov and M.S. Shraiber first devized a circular thin-layer chromatogram,1 which was called spread layer or spot chromatography at the time.
Latest:
Assay for ppm Levels of Azide in Drug SubstancesThe removal of azide as a potential impurity from a drug substance may be critical to its safety profile. The quantitation of this impurity is an important control parameter. This article describes a simple and practical assay for azide using chemical derivatization and HPLC. The method is shown to be suitable for the intended purpose on three example test materials. Potential issues for wider applications are discussed.
Latest:
Sampling: The Ghost in Front of the Laboratory DoorSampling can be the most demanding part of an analysis. Anybody in charge of sampling needs a good understanding of the composition of the material to be investigated, its heterogeneity (or homogeneity, in simple cases), and the chemical properties of the analytes. Sampling procedures must be described in detail. Detecting the bias of a sampling procedure can be difficult; this fact is trivial, but it must not be forgotten.
Latest:
Multiresidue Pesticide Analysis in Onion by a Modified QuEChERS Extraction and Ion Trap GC–MSn AnalysisMost recently formulated pesticides are smaller in molecular weight and designed to break down rapidly in the environment.
Latest:
Removal of Endogenous Matrix Components Using EVOLUTE® CX Mixed-Mode Cation Exchange Solid Phase ExtractionSample preparation is an essential technique to remove unwanted matrix components prior to LC–MS-MS analysis of drugs in biological fluids. Plasma matrix components whether endogenous (salts, proteins, and phospholipids) or exogenous (dosing vehicles, e.g. PEG 400), can interfere with compounds of interest leading to regions of ion suppression or enhancement. This can lead to inaccurate quantitation and have adverse effects on sensitivity. Mixed-mode SPE provides cleaner extracts as a result of rigorous interference wash steps, afforded by the dual retention mechanism of the sorbents.
Latest:
Advances in Chromatography Using Artificial Intelligence and Machine LearningScientists from the University of Turin, Italy have learned how to combine their complementary competencies in analytical chemistry and big data analytics to achieve significant advances in food science and health.
Latest:
Removal of Endogenous Matrix Components Using EVOLUTE® CX Mixed-Mode Cation Exchange Solid Phase ExtractionSample preparation is an essential technique to remove unwanted matrix components prior to LC–MS-MS analysis of drugs in biological fluids. Plasma matrix components whether endogenous (salts, proteins, and phospholipids) or exogenous (dosing vehicles, e.g. PEG 400), can interfere with compounds of interest leading to regions of ion suppression or enhancement. This can lead to inaccurate quantitation and have adverse effects on sensitivity. Mixed-mode SPE provides cleaner extracts as a result of rigorous interference wash steps, afforded by the dual retention mechanism of the sorbents.
Latest:
Tips for Maximizing the Performance of Core-Shell ColumnsA key advantage of core-shell columns is that their performance can rival that of the traditional fully porous particle columns, but at somewhat larger particle sizes and at significantly lower backpressures.
