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Validation of an Aqueous Normal Phase Chromatography Method for the Analysis of Ergothioneine in Commercial MushroomsThe authors developed a new analytical HPLC method using a silica hydride-based column to analyze mushrooms.
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Target Compound Analysis: A Step Ahead Using LC–ESI-TOF Mass SpectrometryLC–MS–MS methods for the unambiguous identification and quantification of pesticides in complex matrix samples are well known and widely used. Triple quadrupole systems have proven useful for this task because of their high specificity in MS–MS mode and their low detection limits. However, working in targetted MS–MS mode prevents the detection of other compounds.
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HPLC–SPE–NMR — A Novel Hyphenation TechniqueHigh performance liquid chromatography–solid phase extraction–nuclear magnetic resonance (HPLC–SPE–NMR) is a novel hyphenation technology that concentrates single chromatographic peaks to elution volumes matching those of NMR flow probes. The SPE unit facilitates the solvent exchange from the mobile phase of the optimized HPLC assay to a deuterated NMR solvent. The well-defined NMR solvent conditions make spectra comparisons feasible, which means databases and spectra catalogues can be used to swiftly identify analytes. The ability to accumulate analytes on the SPE cartridges by multiple trapping reduces the need to perform residual solvent suppression experiments and allows heteronuclear NMR experiments to be performed overnight. Structure elucidation of natural products directly from crude extract HPLC samples has become the key application of this technique.
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Single Calibrant Quantification with HPLC — Fact or Fantasy?This article assesses the extent to which some familiar HPLC detectors can provide reliable quantitative analytical measurements when no suitable primary reference standard exists. The advantages and limitations of two candidate detector schemes are discussed ? evaporative light-scattering detection (ELSD) and chemiluminescent nitrogen detection (CLND). It was found that when the ERETIC (Electronic REference To access In-vivo Concentrations) method in proton NMR was used as a "gold standard" reference procedure the ability of CLND to provide reliable single calibrant quantification is superior to ELSD. Furthermore, ELSD showed bias towards underestimation of chromatographically-resolved impurities, resulting in an overestimation of analyte purity.
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Analysis of Various Cyanobacterial Toxins by LC–MSThis article focuses on the initial development of an LC–MS method to screen for cyanotoxins at low parts-per-billion levels.
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The Development of the Amino Acid AnalyzerThis installment of "Milestones in Chromatography" discusses the events leading to the development of the amino acid analyzer near the end of the 1950s at the Rockefeller Institute of Medical Research by Moore, Stein, and Spackman.
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IC–ICP–MS for Monitoring the Fate of Iodinated X-ray Contrast Media after OzonationThis article shows the potential of IC–ICP–MS for monitoring iodine-containing ionic oxidation by-products that form during ozonation of iodinated X-ray contrast media.
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Single Calibrant Quantification with HPLC — Fact or Fantasy?This article assesses the extent to which some familiar HPLC detectors can provide reliable quantitative analytical measurements when no suitable primary reference standard exists. The advantages and limitations of two candidate detector schemes are discussed ? evaporative light-scattering detection (ELSD) and chemiluminescent nitrogen detection (CLND). It was found that when the ERETIC (Electronic REference To access In-vivo Concentrations) method in proton NMR was used as a "gold standard" reference procedure the ability of CLND to provide reliable single calibrant quantification is superior to ELSD. Furthermore, ELSD showed bias towards underestimation of chromatographically-resolved impurities, resulting in an overestimation of analyte purity.
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Chemometrical Experimental Design-Based Optimization Studies in Capillary Electrophoresis ApplicationsA synopsis of our work detailing the use of chemometric response surface methodology (RSM) in two capillary electrophoresis (CE) studies is described.
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Asymmetric Flow Field-Flow Fractionation (AF4) with Multi-Angle Light Scattering (MALS) for High-Throughput Protein RefoldingOne of the biggest problems facing researchers involved in pharmacogenomics is analysing the recombinant proteins of interest to monitor if they are in a folded state. This article describes a rapid and economical method using asymmetric flow field-flow fractionation combined with multi-angle light scattering (AF4–MALS) to characterize refolded proteins, which overcomes some of the disadvantages associated with other techniques.
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LC–MS-MS Total Drug Analysis of Biological Samples Using a High-Throughput Protein Precipitation MethodThis article describes the use of a 96-well, solvent-resistant filtration plate for total drug analysis in blood plasma.
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Sorptive Tape Extraction — A Novel Sampling Method for the in vivo Study of SkinAn important prerequisite of a good sampling procedure for skin sebum is its reproducibility.
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2D Polymer LC as a High-Speed, High-Throughout Application2D polymer liquid chromatography is a powerful tool for the deformulation of complex samples; however, it is considered to be very specialized and time-consuming. This article shows how recent hardware and software improvements have led to the technique becoming a method for routine analysis.
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Glyphosate and AMPA in Drinking Water: Determination Using Ion Chromatography with Pulsed Amperometric DetectionIn March 2015, the International Agency for Research on Cancer (IARC) published a report that stated that glyphosate was “probably carcinogenic to humans”. Ever since, the use of this chemical has been highly controversial. In some countries, including the USA and Australia, there are already limit values in effect for the weed killer.
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Evaluation of Achiral Stationary Phases for Gradient Screening with Supercritical Fluid ChromatographyUnlike reversed-phase liquid chromatography, SFC lacks a universal stationary phase. Thus, it is important to re-evaluate the default column screening library used with SFC. In this study, three uncommon achiral SFC columns were investigated and compared to three popular stationary phases.
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Breaking Down Barriers: Can LC–MS Revolutionize the Quantitation of Drug Product Impurities?The authors test and compare performance of three types of LC–MS systems for precision, linearity, selectivity, accuracy, and sensitivity in the quantitation of drug impurities.
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Strategies for The Purification of Synthetic Products in The Pharmaceutical IndustryBy taking advantage of the benefits provided by normal-phase mode, highly productive and cost-effective strategies for high-throughput purification of drug discovery products have been developed in the analytical laboratories at Lilly-Spain. The straightforward scaling-up of generic protocols from an analytical to a preparative scale has yielded successful results not only when working in HPLC but also when transferring conditions to other standard low and medium pressure chromatographic systems that are routinely used by synthetic chemists.
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MS Detection of Waste in Public Swimming FacilitiesIs your swimming pool clean and safe? Recreational water illness, most commonly in the form of digestive tract illness or skin, ear, or respiratory infections, is often caused by water contamination. The authors present a robust method, using solid-phase extraction and high-resolution mass spectrometry, for monitoring swimming pool water.
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The Role of Chromatography in the Characterization and Analysis of Protein Therapeutic DrugsChromatography has taken a prominent place in the characterization and analysis of protein therapeutic drugs and today it plays a critical role in the biotechnology laboratory.
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High-Temperature Liquid ChromatographyThe use of high temperature is playing an increasingly important role in high performance liquid chromatography (HPLC) method development and optimization. Major advantages of high-temperature LC (HTLC) include shortened separation time, increased efficiency, and reduction in the use of organic solvent, but the accompanying decrease in mobile phase viscosity provides a lowering of column back pressure, allowing even faster separations, use of longer columns, and use of smaller particles. Here the author summarizes some of the latest findings in HTLC and addresses issues raised when columns and analytes are heated beyond the "normal" operating conditions.
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Evaluation of Fatty Acids as Biochemical Markers for Source Identification of Indian OpiumThis method describes an attempt to identify the source of licit Indian opium based on the fatty acid profile. The analysis was based on gas chromatography (GC) with flame ionization (FID) and mass spectrometric detectors (MS). A total of 124 Indian opium samples were collected and fingerprinted for the presence of various fatty acids. Qualitative analysis of fatty acids indicated the acids such as behenic, stearic and lignoceric were significant biochemical markers, making it a useful method to identify the source of opium for forensic purposes.
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Evaluation of Fatty Acids as Biochemical Markers for Source Identification of Indian OpiumThis method describes an attempt to identify the source of licit Indian opium based on the fatty acid profile. The analysis was based on gas chromatography (GC) with flame ionization (FID) and mass spectrometric detectors (MS). A total of 124 Indian opium samples were collected and fingerprinted for the presence of various fatty acids. Qualitative analysis of fatty acids indicated the acids such as behenic, stearic and lignoceric were significant biochemical markers, making it a useful method to identify the source of opium for forensic purposes.
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Analytical Limbo: How Low Can You Go?September 2006. In analytical chemistry, the continual quest for enhanced sensitivity and specificity - in gas chromatography (GC), this can be equated to separation power - remain the common goal in the development of new analytical methodologies. Today, GC is still the most widely used method for the analysis of volatile and semivolatile organic compounds. When coupled with the right choice of detector for the specific application, a wide linearity range and low limit of detection (LOD) can be met. For GC analyses, many approaches can be used to achieve greater sensitivity and lower LOD. They can be classified broadly into four categories: improved sampling (sample preparation) strategies; sample introduction methods; improved chromatographic performance; and alternative (selective–sensitive) detection transducers. This article provides an up-to-date review of existing and emerging chromatographic innovations, based upon these four strategies, that will improve sensitivity and detection limits of trace..
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Simultaneous Determination of Positive and Negative Counterions Using a Hydrophilic Interaction Chromatography MethodThe authors work to develop a universal high performance liquid chromatography method that is capable of simultaneously retaining and separating both cations and anions within a single chromatographic analysis for the purpose of quantification in pharmaceutical products.
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Evaluation of Fatty Acids as Biochemical Markers for Source Identification of Indian OpiumThis method describes an attempt to identify the source of licit Indian opium based on the fatty acid profile. The analysis was based on gas chromatography (GC) with flame ionization (FID) and mass spectrometric detectors (MS). A total of 124 Indian opium samples were collected and fingerprinted for the presence of various fatty acids. Qualitative analysis of fatty acids indicated the acids such as behenic, stearic and lignoceric were significant biochemical markers, making it a useful method to identify the source of opium for forensic purposes.
