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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.

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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.

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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.

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How to use small columns to test potential biphasic liquid systems for use in large-scale countercurrent chromatography separations

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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.

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A fast and simple sample preparation method for the simultaneous determination of 11 phytohormones in plants by GC–MS has been developed.

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The pyrolysis–GC–MS method enables direct analysis of solid or liquid polymers without sample pretreatment, as illustrated here for various materials, including a dental filling material and a car wrapping foil.

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An analytical method for the global profiling of molecular lipids in biological samples, with particular emphasis on the plasmalogen lipids, is described.

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This article reports an approach to applying intelligent automation for high-throughput LC}MS analysis of compound libraries using Microsoft Visual Basic software.

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An analytical method for the global profiling of molecular lipids in biological samples, with particular emphasis on the plasmalogen lipids, is described.

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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.

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Biotage LLC

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5-Fluorouracil (5-FU) is a low-molecular-weight anticancer drug in clinical use for several solid tumors in humans. Currently, the most widely used methodology for 5-FU quantitation is liquid chromatography–tandem mass spectrometry (LC–MS-MS) with either liquid–liquid extraction (LLE), protein precipitation, or a combination of both as sample cleanup procedures.

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This article focuses on the progression that chiral stationary phases (CSPs), specifically developed for HPLC, are currently undergoing because of the pressing need of an easy switch to UHPLC.

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5-Fluorouracil (5-FU) is a low-molecular-weight anticancer drug in clinical use for several solid tumors in humans. Currently, the most widely used methodology for 5-FU quantitation is liquid chromatography–tandem mass spectrometry (LC–MS-MS) with either liquid–liquid extraction (LLE), protein precipitation, or a combination of both as sample cleanup procedures.

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A method using HR-MS systems to characterize the structures of metabolites is presented. The result is a general workflow for metabolism studies in drug discovery and development.

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Translational proteomics has not been as successful as originally anticipated. Because mass spectrometry (MS) can separate proteins at the sequence level, it provides the selectivity needed for this application; however, traditional challenges still exist, including time-to-result, throughput, and sample-size requirements.

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Stacking and sweeping injection methods are compared and practical suggestions are provided about how to enhance sensitivity for charged and neutral compounds.

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A new method to optimize liquid chromatography (LC) methods using a Quality by Design (QbD) approach is presented. This method is based on the use of design of experiments (DOE) and independent component analysis (ICA) to accurately estimate the modeled responses (that is, the retention times at the beginning, the apex, and the end) of each peak, even for coeluted peaks. This method was applied to the optimization of the separation of nine compounds in a mixture, yielding the design space and the demonstration of robustness of the method.

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The latest applications for carbon nanotubes in chromatography and sample preparation are outlined.

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Recent advances in coating techniques and improved polymers employed as gas chromatographic stationary phases have resulted in commercializing low phase ratio capillary column technology with respectable chromatographic efficiency and inertness.

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The biologically active form of vitamin D is an important analytical target in both research and clinical practice.

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This article focuses on the progression that chiral stationary phases (CSPs), specifically developed for HPLC, are currently undergoing because of the pressing need of an easy switch to UHPLC.

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When forced to teach separation science with little or no access to a laboratory, chromatography simulators can help. Here, we describe several that are both useful and free.

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A novel approach is described for the quantitation of three additives typically used in copper plating using a dual LC system with an ECD and a CAD.