A study of parameters (organic content, additives and pH of the mobile phase) to yield good separation and detection of a series of commercially available free fatty acids ranging from C12:0 (lauric acid) to C18:3 (linolenic acid) using HPLC-CAD is undertaken. Working methods using a C18 silica column were assessed by measuring the experimental limit of detection (LOD) and sensitive ranges with consideration to effects of the Charged Aerosol Detector (CAD) temperature and detector voltage. An isocratic method with high content in acetonitrile and low pH was developed that allowed the CAD detection and quantification of the less volatile fatty acids in the range of from around 1 to 5 ng/uL to over 200 ng/uL. A power fit calibration curve was necessitated since the response of the standards did not display a true linear relationship using linear regression analysis. Conditions or mobile phase additives were not found to increase detection of semi-volatile fatty acids such as lauric acid or myristic acid (C14:0). Column bleed was potentially identified as an unexpected additive that resulted in enhanced peak detection, attributed to the formation or stabilization of bigger aerosol particles. The isocratic method was tested for an olive oil standard using an acetonitrile: 0.01M TFA (96.5:3.5) mobile phase, ion voltage at -300 V, and CAD heater setting of 35°C. Using those conditions, separation and detection of major C16 to C18 fatty acids were achieved although palmitic and oleic acids were not completely resolved. The olive oil analysis showed that relative recovery of the major fatty acid components is consistent and supports the use of HPLC-CAD system for a rapid detection of fatty acids at trace levels.

The first book devoted exclusively to a highly popular, relatively new detection technique Charged Aerosol Detection for Liquid Chromatography and Related Separation Techniques presents a comprehensive review of CAD theory, describes its advantages and limitations, and offers extremely well-informed recommendations for its practical use. Using numerous real-world examples based on contributors’ professional experiences, it provides priceless insights into the actual and potential applications of CAD across a wide range of industries. Charged aerosol detection can be combined with a variety of separation techniques and in numerous configurations. While it has been widely adapted for an array of industrial and research applications with great success, it is still a relatively new technique, and its fundamental performance characteristics are not yet fully understood. This book is intended as a tool for scientists seeking to identify the most effective and efficient uses of charged aerosol detection for a given application. Moving naturally from basic to advanced topics, the author relates fundamental principles, practical uses, and applications across a range of industrial settings, including pharmaceuticals, petrochemicals, biotech, and more. Offers timely, authoritative coverage of the theory, experimental techniques, and end-user applications of charged aerosol detection Includes contributions from experts from various fields of applications who explore CAD’s advantages over traditional HPLC techniques, as well its limitations Provides a current theoretical and practical understanding of CAD, derived from authorities on aerosol technology and separation sciences Features numerous real-world examples that help relate fundamental properties and general operational variables of CAD to its performance in a variety of conditions Charged Aerosol Detection for Liquid Chromatography and Related Separation Techniques is a valuable resource for scientists who use chromatographic techniques in academic research and across an array of industrial settings, including the biopharmaceutical, biotechnology, biofuel, chemical, environmental, and food and beverage industries, among others.

This investigation studied the efficiency of high performance liquid chromatography in the determination of free fatty acids present on the fingertips, and assessed the quantitative relationship between skin fatty acids and the degree of microbial contamination. Automated surgical scrub was utilized to eliminate the microbial contamination. The high performance liquid chromatography provided excellent separation of skin fatty acids for evaluation with the bacterial counts. The fatty acid peaks identified ranged in chain length from C12 through C32. All the fatty acids evaluated showed positive correlation with the bacterial counts with the exception of one acid which had an inverse relationship but none were statistically significant. Finally, the surgical scrub chromatograms showed that the straight chain acids C19 and C21 were lower in concentration than C23 and C25; also, C26 was lower in concentration than C28 and C30. It was evident from the data that fatty acids which have been shown to be bacteriostatic in vitro do not demonstrate the same property on the fingertips. The finding of lower concentration of C19, C21, and C26 than longer chain acids is inconsistent with simple two carbon addition, and indicates there is possible branching at these points in metabolic pathway of fatty acid synthesis. (Author).

This is the fourth volume of an occasional series of review volumes dealing with aspects of lipid methodology. As with the first three volumes, topics have been selected that have been developing rapidly in recent years and have some importance to lipid analysis. The authors are all leading international experts.Topics covered include: analysis of plant lipoxygenase metabolites, preparative high-performance liquid chromatography of lipids, structural analysis of fatty acids, and analysis of stable isotopes in lipids, among others.

This book focuses on the developments in the field of lipid analysis, providing an up-to-date review of the analytical techniques available to chemists and technologists to identify complex molecules. The requisite theoretical background will be provided for individual techniques, together with their strengths and weaknesses, and a guide to the enormous range of commercial applications. It will be an invaluable reference source to all sectors of the oils and fats industry where accurate labeling of foods, food contamination and adulteration are issues of increasing interest and concern.