Lipids and Fatty Acids Lipids are one of the four major biological substances, along with proteins, carbohydrates, and nucleic acids. Fatty acids are also important in living organisms and make up cell membranes (examples: phospholipids, sphingolipids, cholesterol esters). Both play essential roles in the physiology of living organisms, serving as structural components of biological membranes, mediators of energy storage, and signaling molecules within and between cells. Lipids are a general term for substances that are soluble in nonpolar solvents. Nonpolar solvents are usually hydrocarbons,...

Fatty Acids Fatty acid analysis is used in a variety of fields, including food, clinical, and chemical. LC-MS/MS or GC-FID (or GC-MS) is commonly used in fatty acid analysis, and instruments are selected based on analytical purposes and target species. A simple comparison is shown in Fig. 3 and 4. Fig. 4 Instrument comparison based on fatty acid types, sensitivity, and sample preparation • GC-MS is suitable for analyzing the constituent fatty acids in fatty acid esters (e.g., wax, glycerides, and phospholipids), a form in which fatty acids are abundant in the body, as well as free fatty acids,...

Lipids - LC-MS The colanic acid structure constitutes the basic backbone of bile acids and is known to be difficult to fragment by MS/MS. As such, it is difficult to measure fragment ions based on differences in the bile acid structure. In order to accurately quantify various structurally similar bile acids in a simultaneous LC-MS/MS analysis, the isomers must be sufficiently separated by HPLC. In this application, we carefully optimized HPLC conditions for the separation of bile acids and were able to achieve both high throughput and high sensitivity. This is a rapid and versatile quantitative...

Lipids - LC-MS Routine blood tests estimate the total amount of triglycerides, but do not provide quantitative information about the various fatty acids that are bound to triglycerides. Therefore, Shimadzu developed an LC-MS/MS method for the analysis of blood triglycerides as the LC/MS/MS MRM Library for Triglycerides. The developed method analyzes 47 types of triglycerides in blood in 11 minutes (equivalent to 130 analyses per day) and identifies fatty acid combinations in triglycerides. Therefore, it is useful for finding biomarkers in a high-throughput screening. Two types of human plasma...

Lipids – LC-MS Omics Approach with Metabolomics and Lipidomics In the study of living organisms, it is necessary to monitor the target metabolites as well as their precursors and intermediates. In this application, an omics approach was employed by evaluating metabolic changes (i.e., metabolomics) and combining the evaluation results with lipidomics on phospholipids. LC/MS/MS MRM Library for Phospholipid Profiling realizes a trouble-free data analysis. For the metabolite analysis, the non-ion pair method of the LC/ We cultured E. coli in a jar fermenter using a media supplemented with 50 mM thiosulfate...

Lipids – LC-MS Determination of Glucosylceramides in Supplements Glucosylceramides cannot be analyzed by an ultraviolet-visible (UV-VIS) detector as they have little light absorption. Also, in terms of LC, It is common to use a normalphase mode (e.g., chloroform as a mobile phase) and determine the total content because glucosylceramide species vary widely. In such an analysis, the molecular species are eluted together without separation. The Evaporative Light Scattering Detector (ELSD) is a versatile detector that measures the scattered light of a target component after atomizing and vaporizing...

Fatty Acids – GC-MS Analysis of Short-Chain Fatty Acids in Plasma Application Short-chain fatty acids easily evaporate due to their low boiling points, making them difficult to quantitate. GC/MS requires derivatization of the hydroxyl group, but many derivatization steps require water present in the sample to be dried before the derivatization. During this process, much of the short-chain fatty acid is lost due to evaporation. In this application, short-chain fatty acids were derivatized with amines to enable GC/MS analysis. A simple derivatization method makes it possible to analyze short-chain...

Fatty Acids – GC-MS Quantitation of Fatty Acid Methyl Esters (FAMEs) FAMEs are prone to fragmentation during ionization and many similar low mass ions are detected. In this application, CI-MRM was used to combat this problem. CI-MRM by GC-MS/MS fragments ionized protonated molecules by CID, improving mass separation between impurities and FAMEs. • PCI-MRM is more sensitive than EI-MRM, especially for unsaturated fatty acids, and is ideal for fatty acid analysis. • The Smart EI/CI ion source can switch between EI and PCI methods without breaking vacuum • The Smart Metabolites Database and a fatty...

Fatty Acids – LC-MS Analysis of Short-Chain Fatty and Organic Acids in Fecal Samples from Mice Treated with SPF and Antibiotics In general, short-chain fatty acids are highly volatile and hydrophilic, making an LC/MS analysis difficult in a commonly used reversed-phase system. Furthermore, derivatization methods (e.g., trimethylsilylation) widely used for GC/MS require the sample to be dried out, which can result in the loss of volatile components such as short-chain fatty acids. In this application, carboxylic acids were derivatized with 3-nitrophenylhydrazine (3-NPH) in an aqueous solution...

Fatty Acids – LC-MS Analysis of Hydrophilic Metabolites in Saliva Because short-chain fatty acids are not retained on an ODS column, they are prone to co-elute with sample matrix and are less sensitive to detection by a mass spectrometer. In this application, a derivatization with 3-nitrophenylhydrazine (3-NPH) enhanced retention on an ODS column and improved sensitivity with a mass spectrometer. Short-chain fatty acids can be easily analyzed using the LC/MS/MS Method Package for Primary Metabolites Ver. 3 and LCMS-8060NX. For the analysis of short-chain fatty acids, saliva was mixed with Saliva...