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Glycosphingolipids (GSL) are a highly heterogeneous class of lipids representing the majority of the sphingolipid category. GSL are fundamental constituents of cellular membranes that have key roles in various biological processes, such as cellular signaling, recognition, and adhesion. Understanding the structural complexity of GSL is pivotal for unraveling their functional significance in a biological context, specifically their crucial role in the pathophysiology of various diseases. Mass spectrometry (MS) has emerged as a versatile and indispensable tool for the structural elucidation of GSL enabling a deeper understanding of their complex molecular structures and their key roles in cellular dynamics and patholophysiology. Here, we provide a thorough overview of MS techniques tailored for the analysis of GSL, emphasizing their utility in probing GSL intricate structures to advance our understanding of the functional relevance of GSL in health and disease. The application of tandem MS using diverse fragmentation techniques, including novel ion activation methodologies, in studying glycan sequences, linkage positions, and fatty acid composition is extensively discussed. Finally, we address current challenges, such as the detection of low-abundance species and the interpretation of complex spectra, and offer insights into potential solutions and future directions by improving MS instrumentation for enhanced sensitivity and resolution, developing novel ionization techniques, or integrating MS with other analytical approaches for comprehensive GSL characterization., (© 2024. The Author(s).)

Reversed-phase ultrahigh-performance liquid chromatography-mass spectrometry (RP-UHPLC/MS) method was developed with the aim to unambiguously identify a large number of lipid species from multiple lipid classes in human plasma. The optimized RP-UHPLC/MS method employed the C18 column with sub-2-μm particles with the total run time of 25 min. The chromatographic resolution was investigated with 42 standards from 18 lipid classes. The UHPLC system was coupled to high-resolution quadrupole-time-of-flight (QTOF) mass analyzer using electrospray ionization (ESI) measuring full-scan and tandem mass spectra (MS/MS) in positive- and negative-ion modes with high mass accuracy. Our identification approach was based on m/z values measured with mass accuracy within 5 ppm tolerance in the full-scan mode, characteristic fragment ions in MS/MS, and regularity in chromatographic retention dependences for individual lipid species, which provides the highest level of confidence for reported identifications of lipid species including regioisomeric and other isobaric forms. The graphs of dependences of retention times on the carbon number or on the number of double bond(s) in fatty acyl chains were constructed to support the identification of lipid species in homologous lipid series. Our list of identified lipid species is also compared with previous publications investigating human blood samples by various MS-based approaches. In total, we have reported more than 500 lipid species representing 26 polar and nonpolar lipid classes detected in NIST Standard reference material 1950 human plasma., (© 2021. Springer-Verlag GmbH Germany, part of Springer Nature.)

Ultrahigh-performance supercritical fluid chromatography-mass spectrometry (UHPSFC/MS) has a great potential for the high-throughput lipidomic quantitation of biological samples; therefore, the full optimization and method validation of UHPSFC/MS is compared here with ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC/MS) in hydrophilic interaction liquid chromatography (HILIC) mode as the second powerful technique for the lipid class separation. First, the performance of six common extraction protocols is investigated, where the Folch procedure yields the best results with regard to recovery rate, matrix effect, and precision. Then, the full optimization and analytical validation for eight lipid classes using UHPSFC/MS and HILIC-UHPLC/MS methods are performed for the same sample set and applied for the lipidomic characterization of pooled samples of human plasma, human serum, and NIST SRM 1950 human plasma. The choice of appropriate internal standards (IS) for individual lipid classes has a key importance for reliable quantitative workflows illustrated by the selectivity while validation and the calculation of the quantitation error using multiple internal standards per lipid class. Validation results confirm the applicability of both methods, but UHPSFC/MS provides some distinct advantages, such as the successful separation of both non-polar and polar lipid classes unlike to HILIC-UHPLC/MS, shorter total run times (8 vs. 10.5 min), and slightly higher robustness. Various types of correlations between methods (UHPSFC/MS and HILIC-UHPLC/MS), biological material (plasma and serum), IS (laboratory and commercially mixtures), and literature data on the standard reference material show the intra- and inter-laboratory comparison in the quantitation of lipid species from eight lipid classes, the concentration differences in serum and plasma as well as the applicability of non-commercially available internal standard mixtures for lipid quantitation.

Lipidomic analysis of biological samples in a clinical research represents challenging task for analytical methods given by the large number of samples and their extreme complexity. In this work, we compare direct infusion (DI) and chromatography - mass spectrometry (MS) lipidomic approaches represented by three analytical methods in terms of comprehensiveness, sample throughput, and validation results for the lipidomic analysis of biological samples represented by tumor tissue, surrounding normal tissue, plasma, and erythrocytes of kidney cancer patients. Methods are compared in one laboratory using the identical analytical protocol to ensure comparable conditions. Ultrahigh-performance liquid chromatography/MS (UHPLC/MS) method in hydrophilic interaction liquid chromatography mode and DI-MS method are used for this comparison as the most widely used methods for the lipidomic analysis together with ultrahigh-performance supercritical fluid chromatography/MS (UHPSFC/MS) method showing promising results in metabolomics analyses. The nontargeted analysis of pooled samples is performed using all tested methods and 610 lipid species within 23 lipid classes are identified. DI method provides the most comprehensive results due to identification of some polar lipid classes, which are not identified by UHPLC and UHPSFC methods. On the other hand, UHPSFC method provides an excellent sensitivity for less polar lipid classes and the highest sample throughput within 10min method time. The sample consumption of DI method is 125 times higher than for other methods, while only 40μL of organic solvent is used for one sample analysis compared to 3.5mL and 4.9mL in case of UHPLC and UHPSFC methods, respectively. Methods are validated for the quantitative lipidomic analysis of plasma samples with one internal standard for each lipid class. Results show applicability of all tested methods for the lipidomic analysis of biological samples depending on the analysis requirements., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Rationale: Triacylglycerols (TG) contain three fatty acyls attached to the glycerol backbone in stereochemically numbered positions sn-1, 2 and 3. Isobaric TG with exchanged fatty acyl chains in positions sn-1/3 vs. sn-2 are referred to as regioisomers and the determination of their regioisomeric ratios is important for nutrition purposes., Methods: Differential mobility spectrometry (DMS) coupled to electrospray ionization mass spectrometry (ESI-MS) is applied for the separation of simple unsaturated TG regioisomers extracted from porcine adipose tissue using their silver-ion molecular adducts., Results: Four pairs of TG regioisomers containing combinations of unsaturated and saturated fatty acyl chains are successfully separated using DMS with 1-butanol or 1-propanol as the chemical modifier. Various experimental parameters are carefully optimized, such as the separation and compensation voltages applied to DMS electrodes, the type and flow rate of chemical modifier and the dwell time of analyte ions in the DMS cell. The optimized DMS approach is used for the characterization of TG regioisomers in less than one minute, compared to tens of minutes typical for silver-ion or reversed-phase high-performance liquid chromatography/mass spectrometry approaches., Conclusions: The application of this method for the characterization of TG regioisomers in porcine adipose tissue shows the method suitability for analyses of other animal fats.

A novel normal-phase (NP) ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC/MS) method is developed for a separation and quantitation of nonpolar lipid classes occurring in human plasma, erythrocytes and plasma lipoprotein fractions. The baseline class separation of cholesteryl esters (CE), cholesterol, triacylglycerols (TG), regioisomers of 1,2- and 1,3-diacylglycerols (DG) and 1-monoacylglycerols (1-MG) is achieved using an optimized hexane - 2-propanol-acetonitrile mobile phase within 18min for all nonpolar lipid classes or only 9min excluding monoacylglycerols not detected in studied samples. The determination of individual nonpolar lipid classes is performed by the response factor approach and the use of dioleoyl ethylene glycol as a single internal standard. Polar lipid classes, such as phosphatidylglycerols (PG), phosphatidylethanolamines (PE), phosphatidylcholines (PC), sphingomyelins (SM) and lysophosphatidylcholines (LPC), are separated by hydrophilic interaction liquid chromatography (HILIC) using 5mmol/L aqueous ammonium acetate-methanol-acetonitrile gradient within 13minutes. The quantitation of polar lipid classes is done by a similar approach as for nonpolar lipid classes, but a different internal standard (sphingosyl PE d17:1/12:0) is used. The complementary information on fatty acyl profiles after the transesterification of the total lipid extract is obtained by gas chromatography with flame ionization detection (GC/FID). The applicability of developed methodology for fast and comprehensive characterization of blood lipidome is illustrated on samples of human plasma, erythrocytes, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) fractions., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this work, the first systematic characterization of triacylglycerol (TG) enantiomers in real samples using chiral high-performance liquid chromatography (HPLC) with atmospheric pressure chemical ionization mass spectrometry (APCI-MS) is performed. Our chiral HPLC/APCI-MS method is based on the use of two cellulose-tris-(3,5-dimethylphenylcarbamate) columns connected in series using a gradient of hexane-2-propanol mobile phase. All TG enantiomers containing 1-8 DBs and different fatty acyl chain lengths are separated using our chiral HPLC method except for TGs having a combination of saturated and di- or triunsaturated fatty acyls in sn-1 and sn-3 positions. In our work, the randomization reaction of monoacyl TG standards is used for the preparation of all TG enantiomers and regioisomers in a mixture, while the stereospecific esterification of 1,2- or 2,3-isopropylidene-sn-glycerols by selected fatty acids is used for the synthesis of TG enantiomers. The composition of TG enantiomers and regioisomers in hazelnut oil and human plasma samples is determined. Unsaturated fatty acids are preferentially esterified in sn-2 position in hazelnut oil, while no significant preference of saturated or unsaturated fatty acyls is observed in case of human plasma sample. Fatty acids with the higher number of DBs are preferred in sn-1 position of TG enantiomers in hazelnut oil unlike to moderate sn-3 preference in human plasma. The characterization of cholesteryl esters from TG fraction of human plasma sample using our chiral HPLC/APCI-MS method is presented as well.

This review summarizes the state-of-art in liquid chromatography-mass spectrometry (LC-MS) and related techniques with the main focus on recent developments in the last decade. LC-MS records an enormous growth in recent years due to the application potential in analytical chemistry, biochemistry, pharmaceutical analysis, clinical analysis and many other fields, where the qualitative and quantitative characterization of complex organic, bioorganic and organometallic mixtures is needed. Beginners and moderately experienced LC-MS users may be confused by the number of different LC-MS systems on the market, therefore an actual overview of mass spectrometers designed for the LC-MS configuration and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) from main manufacturers is compiled here together with an independent assessment of their advantages and limitations. Current trends in terms of mass analyzers, ionization techniques, fast LC-MS, LC-MALDI-MS, ion mobility spectrometry used in LC-MS, quantitation issues specific to MS and emerging mass spectrometric approaches complementary to LC-MS are discussed as well., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Fatty acid (FA) and triacylglycerol (TG) composition of natural oils and fats intake in the diet has a strong influence on the human health and chronic diseases. In this work, non-aqueous reversed-phase (NARP) and silver-ion high-performance liquid chromatography with atmospheric pressure chemical ionization mass spectrometry detection and gas chromatography with flame-ionization detection (GC/FID) and mass spectrometry detection are used for the characterization of FA and TG composition in complex samples of animal fats from fallow deer, red deer, sheep, moufflon, wild boar, cock, duck and rabbit. The FA composition of samples is determined based on the GC/FID analysis of FA methyl esters. In total, 81 FAs of different acyl chain length, double bond (DB) number, branched/linear, cis-/trans- and DB positional isomers are identified. TGs in animal fats contain mainly monounsaturated and saturated FAs. High amounts of branched and trans-FAs are observed in the samples of ruminants. In NARP mode, individual TG species are separated including the separation of trans- and branched TGs. Silver-ion mode provides the separation of TG regioisomers, which enables the determination of their ratios. Great differences in the preference of unsaturated and saturated FAs in the sn-2 position on the glycerol skeleton are observed among individual animal fats. Unsaturated FAs are preferentially occupied in the sn-2 position in all animal samples except for wild boar with the strong preference of saturated FAs in the sn-2 position., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Silver-ion high-performance liquid chromatography (HPLC) coupled to atmospheric pressure chemical ionization mass spectrometry (APCI-MS) is used for the regioisomeric analysis of triacylglycerols (TGs). Standard mixtures of TG regioisomers are prepared by the randomization reaction from 8 mono-acid TG standards (tripalmitin, tristearin, triarachidin, triolein, trielaidin, trilinolein, trilinolenin and tri-gamma-linolenin). In total, 32 different regioisomeric doublets and 11 triplets are synthesized, separated by silver-ion HPLC using three serial coupled chromatographic columns giving a total length of 75cm. The retention of TGs increases strongly with the double bond (DB) number and slightly for regioisomers having more DBs in sn-1/3 positions. DB positional isomers (linolenic vs. γ-linolenic acids) are also separated and their reverse retention order in two different mobile phases is demonstrated. APCI mass spectra of all separated regioisomers are measured on five different mass spectrometers: single quadrupole LC/MSD (Agilent Technologies), triple quadrupole API 3000 (AB SCIEX), ion trap Esquire 3000 (Bruker Daltonics), quadrupole time-of-flight micrOTOF-Q (Bruker Daltonics) and LTQ Orbitrap XL (Thermo Fisher Scientific). The effect of different types of mass analyzer on the ratio of [M+H-R(i)COOH](+) fragment ions in APCI mass spectra is lower compared to the effect of the number of DBs, their position on the acyl chain and the regiospecific distribution of acyl chains on the glycerol skeleton. Presented data on [M+H-R(i)COOH](+) ratios measured on five different mass analyzers can be used for the direct regioisomeric determination in natural and biological samples., (Copyright © 2010 Elsevier B.V. All rights reserved.)

The growth of the field of lipidomic analysis is enormous with numerous papers published annually, as shown on the statistics from Web of Science for keywords "lipidomic(s)" and "mass spectrometry" (Fig. The detailed analysis of these papers shows the approximate relative portions for major analytical approaches in lipidomic analysis: 59% liquid chromatography, 29% shotgun (direct infusion), and 12% mass spectrometry imaging. Is almost exclusively based on mass spectrometry (MS) analysis [[7]], starting from low-resolution analyzers (typical QqQ), now shifting more towards tandem mass analyzers with ultrahigh resolving power, e.g., Orbitraps. [Extracted from the article]

Matrix-assisted laser desorption/ionization coupled with Orbitrap mass spectrometry (MALDI-Orbitrap-MS) is used for the clinical study of patients with renal cell carcinoma (RCC), as the most common type of kidney cancer. Significant changes in sulfoglycosphingolipid abundances between tumor and autologous normal kidney tissues are observed. First, sulfoglycosphingolipid species in studied RCC samples are identified using high mass accuracy full scan and tandem mass spectra. Subsequently, optimization, method validation, and statistical evaluation of MALDI-MS data for 158 tissues of 80 patients are discussed. More than 120 sulfoglycosphingolipids containing one to five hexosyl units are identified in human RCC samples based on the systematic study of their fragmentation behavior. Many of them are recorded here for the first time. Multivariate data analysis (MDA) methods, i.e., unsupervised principal component analysis (PCA) and supervised orthogonal partial least square discriminant analysis (OPLS-DA), are used for the visualization of differences between normal and tumor samples to reveal the most up- and downregulated lipids in tumor tissues. Obtained results are closely correlated with MALDI mass spectrometry imaging (MSI) and histologic staining. Important steps of the present MALDI-Orbitrap-MS approach are also discussed, such as the selection of best matrix, correct normalization, validation for semiquantitative study, and problems with possible isobaric interferences on closed masses in full scan mass spectra. [ABSTRACT FROM AUTHOR]

Monepantel (MOP) is a new anthelmintic drug intended for the treatment and control of gastrointestinal roundworms (nematodes) infection and associated disease in sheep. The aim of our study was to find out metabolic pathways of MOP in sheep in vivo and in its parasite Haemonchus contortus ex vivo. MOP biotransformation in two H. contortus strains with different sensitivity to anthelmintics was also compared. Ultra high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) technique is used for the identification of MOP metabolites in ovine urine, faeces, and nematodes. MOP biotransformation study in sheep in vivo led to the identification of 13 MOP metabolites; 7 of them have not been described previously in in vitro study. The study of MOP biotransformation in H. contorus ex vivo reveals four MOP metabolites. The nitrile hydrolysis as a new biotransformation pathway in helminths ex vivo is reported here for the first time. Unlike sheep, H. contorus nematodes are not able to metabolize MOP via phase II biotransformation. Nematodes of resistant White river (WR) strain form more types of MOP metabolites than nematodes of sensitive inbred susceptible Edinburgh (ISE) strain. Based on obtained results, schemes of metabolic pathways of MOP in sheep and nematodes are proposed. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The combination of ultrahigh-resolution mass spectrometry imaging (UHRMSI) and ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC/MS/MS) was used for the identification and the spatial localization of atorvastatin (AT) and its metabolites in rat tissues. Ultrahigh-resolution and high mass accuracy measurements on a matrix-assisted laser desorption/ionization (MALDI)-Orbitrap mass spectrometer allowed better detection of desired analytes in the background of matrix and endogenous compounds. Tandem mass spectra were also used to confirm the identification of detected metabolites in complex matrices. The optimization of sample preparation before imaging experiments included the tissue cryogenic sectioning (thickness 20 μm), the transfer to stainless steel or glass slide, and the selection of suitable matrix and its homogenous deposition on the tissue slice. Thirteen matrices typically used for small molecule analysis, e.g., 2,5-dihydroxybenzoic acid (DHB), 1,5-diaminonaphthalene (DAN), 9-aminoacridine (AA), etc., were investigated for the studied drug and its metabolite detection efficiency in both polarity modes. Particular matrices were scored based on the strength of extracted ion current (EIC), relative ratio of AT molecular adducts, and fragment ions. The matrix deposition on the tissue for the most suitable matrices was done by sublimation to obtain the small crystal size and to avoid local variations in the ionization efficiency. UHPLC/MS profiling of drug metabolites in adjacent tissue slices with the previously optimized extraction was performed in parallel to mass spectrometry imaging (MSI) measurements to obtain more detailed information on metabolites in addition to the spatial information from MSI. The quantitation of atorvastatin in rat liver, serum, and feces was also performed. [ABSTRACT FROM AUTHOR]

Ultrahigh-performance liquid chromatography coupled with high-mass-accuracy tandem mass spectrometry (UHPLC-MS-MS) has been used for elucidation of the structures of oxidation products of atorvastatin (AT), one of the most popular commercially available drugs. The purpose of the study was identification of AT metabolites in rat hepatocytes and comparison with electrochemically generated oxidation products. AT was incubated with rat hepatocytes for 24 h. Electrochemical oxidation of AT was performed by use of a three-electrode off-line system with a glassy carbon working electrode. Three supporting electrolytes (0.1 mol L HSO, 0.1 mol L HCl, and 0.1 mol L NaCl) were tested, and dependence on pH was also investigated. AT undergoes oxidation by a single irreversible process at approximately +1.0 V vs. Ag/AgCl electrode. The results obtained revealed a simple and relatively fast way of determining the type of oxidation and its position, on the basis of characteristic neutral losses (NLs) and fragment ions. Unfortunately, different products were obtained by electrochemical oxidation and biotransformation of AT. High-mass-accuracy measurement combined with different UHPLC-MS-MS scans, for example reconstructed ion-current chromatograms, constant neutral loss chromatograms, or exact mass filtering, enable rapid identification of drug-related compounds. β-Oxidation, aromatic hydroxylation of the phenylaminocarbonyl group, sulfation, AT lactone and glycol formation were observed in rat biotransformation samples. In contrast, a variety of oxidation reactions on the conjugated skeleton of isopropyl substituent of AT were identified as products of electrolysis. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: This review summarizes the basic rules for the interpretation of atmospheric pressure ionization (API) mass spectra of small molecules written with the style primarily intended for beginners and low-experienced researchers with the mass spectra interpretation. The first and basic step in any interpretation of mass spectra is always the determination of molecular weight, which is relatively easy in case of soft ionization techniques due to the limited extend of fragmentation and the prevailing presence of (de)protonated molecules in the full scan mass spectra. These [M+H]+ and [M−H]− ions are often accompanied by low abundant molecular adducts, which can be used as the supplementary information for the unambiguous determination of molecular weights. In certain cases, adduct ions may dominate the spectra. The subsequent interpretation of full scan and tandem mass spectra is more complicated due to a high number of possible functional groups, structural subunits and their combinations resulting in numerous competitive fragmentation pathways. Typical neutral losses and the effect of individual functional groups on the fragmentation are discussed in detail and illustrated with selected examples. Modern mass analyzers have powerful features for the structural elucidation, for example high resolving power, high mass accuracy, multistage tandem mass spectrometry, dedicated softwares for the interpretation of mass spectra and prediction of their fragmentation. Background information on differences among individual ionization techniques suitable for the HPLC–MS coupling and basic types of mass analyzers with consequences for the data interpretation is briefly discussed as well. Selected examples illustrate that the right optimization of chromatographic separation and the use of other than mass spectrometric detectors can bring valuable complementary information. [Copyright &y& Elsevier]

Abstract: The selection of column packing during the development of high-performance liquid chromatography method is a crucial step to achieve sufficient chromatographic resolution of analyzed species in complex mixtures. Various stationary phases are tested in this paper for the analysis of complex mixture of triacylglycerols (TGs) in blackcurrant oil using non-aqueous reversed-phase (NARP) system with acetonitrile–2-propanol mobile phase. Conventional C18 column in the total length of 45cm is used for the separation of TGs according to their equivalent carbon number, the number and positions of double bonds and acyl chain lengths. The separation of TGs and their more polar hydrolysis products after the partial enzymatic hydrolysis of blackcurrant oil in one chromatographic run is achieved using conventional C18 column. Retention times of TGs are reduced almost 10 times without the loss of the chromatographic resolution using ultra high-performance liquid chromatography with 1.7μm C18 particles. The separation in NARP system on C30 column shows an unusual phenomenon, because the retention order of TGs changes depending on the column temperature, which is reported for the first time. The commercial monolithic column modified with C18 is used for the fast analysis of TGs to increase the sample throughput but at cost of low resolution. [Copyright &y& Elsevier]

• Seventy-eight metabolites covering a large polarity range were investigated. • Unified chromatography allows the comprehensive UHPSFC/MS analysis of biomolecules. • The effect of columns, additives and ion source were studied. • Higher identification confidence was achieved by MSE for human plasma. • 5823 metabolites were identified in human plasma using MSDIAL. The applicability of ultrahigh-performance supercritical fluid chromatography coupled with mass spectrometry (UHPSFC/MS) for the qualitative analysis of metabolites with a wide polarity range (log P: −3.89–18.95) was evaluated using a representative set of 78 standards belonging to nucleosides, biogenic amines, carbohydrates, amino acids, and lipids. The effects of the gradient shape and the percentage of water (1, 2, and 5%) were investigated on the Viridis BEH column. The screening of eight stationary phases was performed for columns with different interaction sites, such as hydrogen bonding, hydrophobic, π-π, or anionic exchange type interactions. The highest number of compounds (67) of the set studied was detected on the Torus Diol column, which provided a resolution parameter of 39. The DEA column had the second best performance with 58 detected standards and the resolution parameter of 54. The overall performance of other parameters, such as selectivity, peak height, peak area, retention time stability, asymmetry factor, and mass accuracy, led to the selection of the Diol column for the final method. The comparison of additives showed that ammonium acetate gave a superior sensitivity over ammonium formate. Moreover, the influence of the ion source on the ionization efficiency was studied by employing atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI). The results proved the complementarity of both ionization techniques, but also the superior ionization capacity of the ESI source in the negative ion mode, for which 53% of the analytes were detected compared to only 7% for the APCI source. Finally, optimized analytical conditions were applied to the analysis of a pooled human plasma sample. 44 compounds from the preselected set were detected in human plasma using ESI-UHPSFC/MS in MSE mode considering both ionization modes. [ABSTRACT FROM AUTHOR]

Abstract: Optimized non-aqueous reversed-phase high-performance liquid chromatography method using acetonitrile–2-propanol gradient elution and the column coupling in the total length of 45cm has been applied for the high resolution separation of plant oils important in food industry, dietetics and cosmetics. Positive-ion atmospheric pressure chemical ionization mass spectrometry is used for the unambiguous identification and also the reliable quantitation with the response factors approach. Based on the precise determination of individual triacyglycerol concentrations, the calculation of average parameters important in the nutrition is performed, i.e. average carbon number, average double bond number, relative concentrations of essential, saturated, monounsaturated and polyunsaturated fatty acids. Results are reported in the form of both chromatographic fingerprints and tables containing relative concentrations for all triacylglycerols and fatty acids in individual samples. In total, 264 triacylglycerols consisting of 28 fatty acids with the alkyl chain length from 6 to 26 carbon atoms and 0 to 4 double bonds have been identified in 26 industrial important plant oils. [Copyright &y& Elsevier]

Electrospray ionization (ESI) is most suitable for dyes with an ionic or very polar character, while atmospheric pressure chemical ionization (APCI) suits better those dyes and pigments with low to medium polarity. The negative-ion mode of ESI is used for anionic dyes such as (poly)sulfonated and/or (poly)sulfated variants, where the series of deprotonated molecules enables an easy determination of molecular weights and the number of acid groups. The positive-ion APCI or ESI mass spectra of non-ionic and cationic dyes and pigments provide typical molecular adducts [M+H]+, [M+Na]+ and [M+K]+ used for the molecular assignment. The first-order mass spectra often suffer from the lack of fragment ions, which can be solved by using multistage tandem mass spectra (MS n ) measured with an ion trap analyzer. The effects of various functional groups on the fragmentation behavior are described herein. The detailed understanding of fragmentation paths enables the correlation among particular functional groups and the fragmentation patterns. The presented approach is applicable for the structural analysis of complex mixtures using HPLC/MS/MS techniques with volatile ion-pairing agents. [Copyright &y& Elsevier]

A novel electrospray ionization (ESI) mass spectrometric approach for the structure elucidation of ionic organotin-(IV) compounds or complexes with weakly bonded ligands as for example monodentate carboxylates or sulfonates is proposed using both positive-ion and negative-ion ESI tandem mass spectra. The ionization mechanism of organotin(IV) compounds involves the cleavage of the most labile bond with an ionic character yielding two complementary ions, [Cat]+ and [An]-. Positively charged species containing tin atom, [Cat]+, are analyzed in the positive-ion mode and negatively charged species without the tin atom, [An]-, in the negative-ion mode. Fragmentation patterns of [C24H29N2Sn]+, [C21H22NSn]+, and [C17H30-NSn]+ ions are proposed based on the detailed interpretation of MSn spectra, which is simplified by an easy recognition of characteristic tin isotopic clusters in particular fragment ions. Proposed fragmentation mechanisms are supported by comparison with MSn spectra of deuterium-labeled analogues. The applicability of this method is illustrated on two sets of organotin(IV) compounds, including seven [2,6-bis(dimethylaminomethyl)-phenyl]diphenyltin(IV) derivatives with small inorganic counteranions X (Br, NO3, SCN, BF4, SeCN, CN, PF6), six organotin(IV) complexes containing two C,N-chelating ligands with azo dyes, and the identification of unknown hydrolysis products. [ABSTRACT FROM AUTHOR]

The title dyes, a group of new homo-bireactive disazo reactive dyes having molecular masses of 1000-1400 Da, were developed because of their potential use as low salt, easy wash-off colorants for cotton. Following dye synthesis from diaminobiphenyls with and without substituents in the 2,2′-positions, negative-ion electrospray ionisation mass spectrometry (ESI-MS) was used to charasterise the dyes. The MS obtained were characterised by signals arising from [M - xH]x- ions plus fragment ions produced by cleavage at C-N bonds adjacent to the azo linkage. In addition, better results were produced when J-acid was the coupler employed rather than H-acid. The characteristic fragmentation behaviour of the studied dyes is discussed and illustrated on selected example. [ABSTRACT FROM AUTHOR]

Triacylglycerols (TGs) and diacylglycerols (DGs) in 16 plant oil samples (hazelnut, pistachio, poppy-seed, almond, palm, Brazil-nut, rapeseed, macadamia, soyabean, sunflower, linseed, Dracocephalum moldavica, evening primrose, corn, amaranth, Silybum arianum) were analyzed by HPLC–MS with atmospheric pressure chemical ionization (APCI) and UV detection at 205 nm on two Nova-Pak C18 chromatographic columns connected in series. A single chromatographic column and non-aqueous ethanol–acetonitrile gradient system was used as a compromise between the analysis time and the resolution for the characterization of TG composition of five plant oils. APCI mass spectra were applied for the identification of all TGs and other acylglycerols. The isobaric positional isomers can be distinguished on the basis of different relative abundances of the fragment ions formed by preferred losses of the fatty acid from sn-1(3) positions compared to the sn-2 position. Excellent chromatographic resolution and broad retention window together with APCI mass spectra enabled positive identification of TGs containing fatty acids with odd numbers of carbon atoms such as margaric (C17:0) and heptadecanoic (C17:1) acids. The general fragmentation patterns of TGs in both APCI and electrospray ionization mass spectra were proposed on the basis of MSn spectra measured with an ion trap analyzer. The relative concentrations of particular TGs in the analyzed plant oils were estimated on the basis of relative peak areas measured with UV detection at 205 nm. [Copyright &y& Elsevier]

Glycosphingolipids (GSL) represent a highly heterogeneous class of lipids with many cellular functions, implicated in a wide spectrum of human diseases. Their isolation, detection, and comprehensive structural analysis is a challenging task due to the structural diversity of GSL molecules. In this work, GSL subclasses are isolated from human plasma using an optimized monophasic ethanol–water solvent system capable to recover a broad range of GSL species. Obtained deproteinized plasma is subsequently purified and concentrated by C18-based solid-phase extraction (SPE). The hydrophilic interaction liquid chromatography coupled to electrospray ionization linear ion trap tandem mass spectrometry (HILIC-ESI-LIT-MS/MS) is used for GSL analysis in the human plasma extract. Our results provide an in-depth profiling and structural characterization of glycosphingolipid and some phospholipid subclasses identified in the human plasma based on their retention times and the interpretation of tandem mass spectra. The structural composition of particular lipid species is readily characterized based on the detailed interpretation of mass spectrometry (MS) and tandem mass spectrometry (MS/MS) spectra and further confirmed by specific fragmentation behavior following predictable patterns, which yields to the unambiguous identification of 154 GSL species within 7 lipid subclasses and 77 phospholipids representing the highest number of GSL species ever reported in the human plasma. The developed HILIC-ESI-MS/MS method can be used for further clinical and biological research of GSL in the human blood or other biological samples. [ABSTRACT FROM AUTHOR]

The author reflects on the lipidomics which is defined as quantitative snapshot of all lipids within a biological system. Topics discussed include several methods for lipidomic analysis, which include tandem and/or high-resolution mass spectrometry (MS), liquid-chromatography (LC/MS), and supercritical fluid chromatography coupling. Also mentioned are polarity, biomarkers, and omics techniques.

Mass spectrometry combined with (ultra)high-performance liquid chromatography has proved to be the most suitable method for the analysis of glycosphingolipids (GSLs). An increasing number of studies have focused on the analysis of not only simple but also complex GSLs with the aim of clarifying their biochemical functions in animals and humans. Despite the tremendous improvements in sample preparation and analytical methods in glycosphingolipidomics, there are still several major issues that complicate the comprehensive analysis of GSLs. This review aims to provide the latest advances, developments, and instrumental innovations in the analysis of GSLs in biological samples. The current barriers and challenges facing the qualitative and quantitative analysis of GSLs are highlighted and critically assessed. Overcoming these bottlenecks is crucial for high-throughput GSLs profiling, which is essential to reveal their clinical potential and to understand their role in the pathophysiology of serious diseases, such as cancer. • Overview of recent advances and current trends in the analysis of GSLs. • Absence of a unique isolation protocol hampers the comprehensive analysis of GSLs. • Challenging separation of GSL isomers is discussed. • Lack of ISs and reference materials complicate the quantitation of GSLs. • Harmonization is urgently needed to translate lipidomics into clinical practice. [ABSTRACT FROM AUTHOR]

LipidQuant 2.1 is a software written in Matlab, which is designed for the high-throughput processing of large lipidomic data sets measured by lipid class separation coupled with quadrupole time-of-flight (QTOF) high-resolution mass spectrometry (MS). The software enables the identification of lipid species based on defined mass accuracy. The main focus is on the right lipidomic quantitation using at least one internal standard per lipid class and the implementation of an automated procedure for Type I and Type II isotopic corrections necessary for the determination of accurate molar concentrations, which is not available for the majority of existing software solutions. LipidQuant 2.1 offers three options for peak assignment, visualization of the isotopic pattern, and automated calculation of m/z for various adduct ions. The initial lipidomic database covers 31 lipid classes with more than 2900 lipid species that occur primarily in the human lipidome, but users have the full flexibility to modify and extend the database according to their needs. All algorithms and the detailed user manual are provided. The reliability of LipidQuant 2.1 is demonstrated on a set of more than 250 biological samples measured by ultrahigh-performance supercritical liquid chromatography (UHPSFC) coupled with QTOF-MS. • Open-source lipidomics software. • Identification and quantification of lipidomic data measured by lipid class separation coupled with full scan QTOF high-resolution MS. • Quantitation includes Type I and Type II isotopic corrections calculated using nonnegative regression. [ABSTRACT FROM AUTHOR]

Silver-ion normal-phase high-performance liquid chromatography (HPLC) provides a superior separation selectivity for lipids differing in the number and position of double bonds in fatty acid chains including the resolution of triacylglycerol (TG) regioisomers under optimized conditions. Our silver-ion HPLC method is based on the coupling of three columns in the total length of 75 cm and a new mobile phase gradient consisting of hexane-aceto-nitrile-2-propanol which provides better resolution and also reproducibility in comparison to previously used mobile phases. In our work, the chemical interesterification (randomization) of single-acid TG standards is used for the generation of regioisomeric series of TGs, because it provides a random distribution of fatty acids in TGs at well-defined concentration ratios. The baseline separation of regioisomeric TG pairs containing up to three double bonds and the partial separation of TG regioisomers with four to seven double bonds are reported for the first time. Our silver-ion high-performance liquid chromatography/ mass spectrometry (HPLC/MS) method is applied for the regioisomeric characterization of complex samples of plant oils and animal fat, where the results clearly demonstrate different preference of sn-2 occupation in plants (mainly unsaturated fatty acids) versus animal fat (mainly saturated fatty acids). [ABSTRACT FROM AUTHOR]

Effects of blood collection tubes, the time period, the sample origin, and the method used on the lipidomic profile are investigated by ultrahigh-performance supercritical fluid chromatography - mass spectrometry (UHPSFC/MS) and hydrophilic interaction liquid chromatography ultrahigh-performance liquid chromatography - mass spectrometry (HILIC-UHPLC/MS). Heparin plasma samples have been obtained from 99 healthy volunteers at three time points separated by six-month intervals together with one collection for EDTA plasma and serum. Furthermore, lipid concentrations in heparin plasma collected at two different sites are compared. 171 lipid species from eight lipid classes are quantified with UHPSFC/MS, and 122 lipid species from four lipid classes with HILIC-UHPLC/MS. The accuracy of both methods is monitored by the quantitation error using two internal standards (IS) per individual lipid classes. No significant differences in lipid profiles are observed for different time points and types of collection tubes (heparin plasma, EDTA plasma, and serum). Most pronounced lipid concentration differences are observed for the comparison of NIST SRM 1950 human plasma and mean lipid concentrations of the investigated cohort. Furthermore, differences in lipid concentrations are observed between employed methods (UHPSFC/MS vs. HILIC-UHPLC/MS), which can be compensated by the normalization using NIST SRM 1950 human plasma used as the quality control sample. Image 1 • Quality control system is developed for the quality assurance of lipidomic quantitation. • Lipidomic profiles are less influenced by the type of blood collection tubes than by the effect of time and collection site. • Method dependent measurement bias can be compensated by the reference value normalization. [ABSTRACT FROM AUTHOR]

A new hydrophilic interaction liquid chromatography - mass spectrometry method is developed for low-abundant phospholipids and sphingolipids in human plasma and serum. The optimized method involves the Cogent Silica type C hydride column, the simple sample preparation by protein precipitation, and the removal of highly abundant lipid classes using the postcolumn valve directed to waste during two elution windows. The method allows a highly confident and sensitive identification of low-abundant lipid classes in human plasma (246 lipid species from 24 lipid subclasses) based on mass accuracy and retention dependencies in both polarity modes. The method is validated for quantitation using two internal standards (if available) for each lipid class and applied to human plasma and serum samples obtained from patients with pancreatic ductal adenocarcinoma (PDAC), healthy controls, and NIST SRM 1950. Multivariate data analysis followed by various statistical projection methods is used to determine the most dysregulated lipids. Significant downregulation is observed for lysophospholipids with fatty acyl composition 16:0, 18:0, 18:1, and 18:2. Distinct trends are observed for phosphatidylethanolamines (PE) in relation to the bonding type of fatty acyls, where most PE with acyl bonds are upregulated, while ether/plasmenyl PE are downregulated. For the sphingolipid category, sphingolipids with very long N-acyl chains are downregulated, while sphingolipids with shorter N-acyl chains were upregulated in PDAC. These changes are consistently observed for various classes of sphingolipids, ranging from ceramides to glycosphingolipids, indicating a possible metabolic disorder in ceramide biosynthesis caused by PDAC. [Display omitted] • New quantitative method for low abundant lipid classes in human plasma and serum. • Lipidomic profiling of patients with pancreatic cancer and healthy controls. • Statistical evaluation and determination of the most dysregulated lipids. • Correlation of dysregulated sphingolipids and phospholipids with their metabolic pathways. [ABSTRACT FROM AUTHOR]

Reversed-phase ultrahigh-performance liquid chromatography (RP-UHPLC) method using two 15 cm sub–2 μm particles octadecylsilica gel columns is developed with the goal to separate and unambiguously identify a large number of lipid species in biological samples. The identification is performed by the coupling with high-resolution tandem mass spectrometry (MS/MS) using quadrupole – time-of-flight (QTOF) instrument. Electrospray ionization (ESI) full scan and tandem mass spectra are measured in both polarity modes with the mass accuracy better than 5 ppm, which provides a high confidence of lipid identification. Over 400 lipid species covering 14 polar and nonpolar lipid classes from 5 lipid categories are identified in total lipid extracts of human plasma, human urine and porcine brain. The general dependences of relative retention times on relative carbon number or relative double bond number are constructed and fit with the second degree polynomial regression. The regular retention patterns in homologous lipid series provide additional identification point for UHPLC/MS lipidomic analysis, which increases the confidence of lipid identification. The reprocessing of previously published data by our and other groups measured in the RP mode and ultrahigh-performance supercritical fluid chromatography on the silica column shows more generic applicability of the polynomial regression for the description of retention behavior and the prediction of retention times. The novelty of this work is the characterization of general trends in the retention behavior of lipids within logical series with constant fatty acyl length or double bond number, which may be used as an additional criterion to increase the confidence of lipid identification. [ABSTRACT FROM AUTHOR]

Ultrahigh-performance supercritical fluid chromatography/mass spectrometry (UHPSFC/MS) is one of the fastest analytical approaches for high-throughput lipidomic analysis covering a wide range of lipid categories and classes. Lipid class separation and lipid species separation are two main separation modes available for the UHPSFC analysis of lipids. The mechanism of the lipid class separation mode is comparable to that of hydrophilic interaction liquid chromatography (HILIC). The direct comparison of HILIC - ultrahigh-performance liquid chromatography (HILIC-UHPLC) and UHPSFC shows the applicability of UHPSFC/MS for high-throughput quantitation of both nonpolar and polar lipid classes, the faster analysis time, and comparable reproducibility and sensitivity. The retention mechanism of the lipid species separation mode is comparable to reversed-phase UHPLC, but the nonpolar character of supercritical carbon dioxide (scCO 2) provides a different selectivity compared to that of conventional RP-UHPLC. The introduction of various hyphenation interfaces to MS broadens the applicability and sensitivity range of UHPSFC/MS using scCO 2 as the main component of the mobile phase. The addition of ionic additives (volatile salts, acids, and bases) to the modifier improves the separation of medium to polar lipids. Furthermore, UHPSFC/MS has also a great potential in the chiral separation of lipids, but the field has not yet been fully explored. • UHPSFC/MS is one of the fastest analytical methods for lipidomic analysis. • Lipid class separation and lipid species separation are two basic approaches in UHPSFC. • UHPSFC/MS high-throughput lipidomic quantitation is well suited for clinical analysis. • Advantages and limitations of UHPSFC/MS and UHPLC/MS are compared. [ABSTRACT FROM AUTHOR]

Lung cancer represents one of the leading worldwide causes of cancer death, but the pathobiochemistry of this disease is still not fully understood. Here we characterize the lipidomic and metabolomic profiles of the tumor and surrounding normal tissues for 23 patients with non-small cell lung cancer. In total, 500 molecular species were identified and quantified by a combination of the lipidomic shotgun tandem mass spectrometry (MS/MS) analysis and the targeted metabolomic approach using liquid chromatography (LC) – MS/MS. The statistical evaluation includes multivariate and univariate methods with the emphasis on paired statistical approaches. Our research revealed significant changes in several biochemical pathways related to the central carbon metabolism, acylcarnitines, dipeptides as well as the disruption in the lipid metabolism observed mainly for glycerophospholipids, sphingolipids, and cholesteryl esters. • Lipidomic and metabolomic profiles measured for 23 patients tissues with non-small cell lung cancer • 500 molecular species were quantified by MS based workflows • Paired statistical evaluation performed by multivariate and univariate methods • Changed pathways related to the central carbon metabolism, acylcarnitines, dipeptides, PL, SL, and CE [ABSTRACT FROM AUTHOR]

Abstract: Galantamine, an alkaloid isolated from the bulbs and flowers of Caucasian snowdrop (Galanthus woronowii, Amaryllidaceae) and related species, is employed in human medicine for the treatment of various neuromuscular and neurodegenerative diseases. After the administration, the products of oxidative biotransformation (O-desmethyl-galantamine, N-desmethyl-galantamine, galantamine-N-oxide) and chiral conversion (epigalantamine) are formed in various concentrations from parent compound. For the identification and determination of galantamine and its phase I metabolites in blood plasma and tissues, a new bioanalytical method based on a reversed-phase high-performance liquid chromatography with UV photodiode-array, fluorescence and mass spectrometric detection was developed, validated and applied to pharmacokinetic and biotransformation studies. Sample preparation included a homogenization of the rat tissues (liver, brain, hypophysis) in a phosphate buffer 0.05mol/L pH 7.4. Plasma samples and tissue homogenates were purified using a mixed-mode solid-phase extraction (Waters Oasis MCX cartridges). Galantamine, its above-mentioned metabolites and the internal standard codeine were separated on a Discovery HS F5 column (Supelco, 150mm×4.6mm I.D., 5μm) at flow rate of 1mL/min using a linear gradient elution. UV photodiode-array and mass spectrometric detection were employed for the identification of individual galantamine metabolites in various biomatrices, the fluorescence detection (λ excit =280nm/λ emiss =310nm) was chosen for the quantification of galantamine and its metabolites. The developed method was applicable in liver tissue in the range from 0.50 to 63.47nmol/g of galantamine, from 0.32 to 41.42nmol/g of O-desmethyl-galantamine, from 0.54 to 69.40nmol/g of N-desmethyl-galantamine and from 0.70 to 89.03nmol/g of epigalantamine. Limit of detection was found to be 0.04nmol/g for galantamine, 0.19nmol/g for O-desmethyl-galantamine, and 0.07nmol/g for N-desmethyl-galantamine and epigalantamine. [Copyright &y& Elsevier]

Abstract: 3-(4-Bromophenyl)-5-acetyloxymethyl-2,5-dihydrofuran-2-one (LNO-18-22) is a representative member of a novel group of potential antifungal drugs, derived from a natural 3,5-disubstituted butenolide, (-)incrustoporine, as a lead structure. This lipophilic compound is characterized by high in vitro antifungal activity and low acute toxicity. For the purpose of in vivo studies, a new bioanalytical high-performance liquid chromatographic method with UV photodiode-array and mass spectrometric detection (HPLC-PDA-MS), involving a direct injection of diluted mouse urine was developed and used in the evaluation of the metabolic profiling of this drug candidate. The separation of LNO-18-22 and its phase I metabolites was performed in 37min on a 125mm×4mm chromatographic column with Purospher RP-18e using an acetonitrile–water gradient elution. Scan mode of UV detection (195–380nm) was employed for the identification of the parent compound and its biotransformation products in the biomatrix. Finally, the identity of LNO-18-22 and its metabolites was confirmed using HPLC-MS analyses of the eluate. These experiments demonstrated the power of a comprehensive analytical approach based on the combination of xenobiochemical methods and the results from tandem HPLC-PDA-MS (chromatographic behaviour, UV and MS spectra of native metabolites versus synthetic standards). The chemical structures of five phase I LNO-18-22 metabolites and one phase II metabolite were elucidated in the mouse urine, with two of these metabolites having very unexpected structures. [Copyright &y& Elsevier]

The lipidomic research is currently devoting considerable effort to the harmonization that should enable the generation of comparable and accurate quantitative lipidomic data across different laboratories and regardless of the mass spectrometry-based platform used. In the present study, we systematically investigate the effects of the experimental setup on quantitative lipidomics data obtained by two lipid class separation approaches, hydrophilic interaction liquid chromatography (HILIC) and ultrahigh-performance supercritical fluid chromatography (UHPSFC), coupled to two different quadrupole – time of flight (QTOF) mass spectrometers from the same vendor. This approach is applied for measurements of 268 human plasma samples of healthy volunteers and renal cell carcinoma patients resulting in four data sets. We investigate and visualize differences among these data sets by multivariate data analysis methods, such as principal component analysis (PCA), orthogonal partial least square discriminant analysis (OPLS-DA), box plots, and logarithmic correlations of molar concentrations of individual lipid species. The results indicate that even measurements in the same laboratory for the same samples using different analytical platforms may yield slight variations in the molar concentrations determined. The normalization to a reference sample with defined lipid concentrations can further diminish these small differences, resulting in highly homogenous molar concentrations of individual lipid species. This strategy indicates a potential approach towards the reporting of comparable quantitative results independent from the quantitative approach and mass spectrometer used, which is important for a wider acceptance of lipidomics data in various biomarker inter-laboratory studies and ring trials. [Display omitted] • Instrument type had a small influence on determined lipid concentrations. • Concentration differences among four analytical platforms were reduced by normalization. • No influence of instrumental setup on statistical models for cancer differentiation. [ABSTRACT FROM AUTHOR]

Ultrahigh-performance supercritical fluid chromatography - mass spectrometry (UHPSFC/MS), ultrahigh-performance liquid chromatography - mass spectrometry (UHPLC/MS), and matrix-assisted laser desorption/ionization (MALDI) - MS techniques were used for the lipidomic characterization of exosomes isolated from human plasma. The high-throughput methods UHPSFC/MS and UHPLC/MS using a silica-based column containing sub-2 μm particles enabled the lipid class separation and the quantitation based on exogenous class internal standards in <7 minute run time. MALDI provided the complementary information on anionic lipid classes, such as sulfatides. The nontargeted analysis of 12 healthy volunteers was performed, and absolute molar concentration of 244 lipids in exosomes and 191 lipids in plasma belonging to 10 lipid classes were quantified. The statistical evaluation of data included principal component analysis, orthogonal partial least square discriminant analysis, S-plots, p-values, T-values, fold changes, false discovery rate, box plots, and correlation plots, which resulted in the information on lipid changes in exosomes in comparison to plasma. The major changes were detected in the composition of triacylglycerols, diacylglycerols, phosphatidylcholines, and lysophosphatidylcholines, whereby sphingomyelins, phosphatidylinositols, and sulfatides showed rather similar profiles in both biological matrices. Unlabelled Image • 3 MS based approaches (UHPSFC/MS, UHPLC/MS, and MALDI) were used for detailed lipidomic characterization of human plasma exosomes • Lipidomic quantitation resulted in the determination of molar concentration of 244 lipids in exosomes and 191 lipids in plasma • Multivariate data analysis methods were used for the visualization of major changes between exosomes and human plasma • Major changes detected for triacylglycerols, diacylglycerols, phosphatidylcholines, and lysophosphatidylcholines [ABSTRACT FROM AUTHOR]

This review summarizes available mass spectrometry (MS) based approaches for the quantitative analysis of lipids in biological samples in the cancer research, which is termed here as oncolipidomics. The methodological part shows possible configurations of stand-alone MS or MS coupled to liquid-phase separation techniques. For the characterization of various lipids with the special emphasis on methods convenient for robust high-throughput lipidomic quantitation of biological samples, such as body fluids, tissues, and cell lines. The critical assessment of lipid species dysregulated in various cancer types is provided with the goal to summarize and generalize the typical up and down regulated lipids associated with the progress of tumor growth and evaluate possible future use of lipidomic analysis in the early cancer diagnosis. • Overview of MS based methods for lipidomic analysis in cancer research. • Basic concepts in the lipidomic quantitation of biological samples. • Dysregulation of lipids in various types of cancer. [ABSTRACT FROM AUTHOR]