Use Of Hydrophilic Interaction Liquid Chromatography Research Articles

Comprehensive metabolite identification study of arterolane using hydrophilic interaction liquid chromatography with quadrupole-time-of-flight mass spectrometry.

In 2012, arterolane (ART) in combination with piperaquine received approval in India for the treatment of plasmodium-induced malaria; however, to date, a detailed metabolite identification study of ART has not been reported. Being polar in nature, ART shows early elution on reversed-phase columns which might be the rate-limiting factor of its systematic analytical studies. We have utilized hydrophilic interaction liquid chromatography (HILIC) to separate in vitro and in vivo metabolites of ART. The possible sites of metabolism were predicted by XenoSite software to obtain an initial assessment. In vitro studies were conducted by incubating the drug with liver microsomes such as human, rat and human S9 fractions. Later, in vivo studies were performed to check the metabolites in urine, faeces and plasma. The samples were pooled and subjected to the protein precipitation method before analysis by liquid chromatography/quadrupole-time-of-flight mass spectrometry (LC/QTOFMS). We have observed 15 metabolites in this study which were phase I metabolites formed due to hydroxylation, dihydroxylation, peroxide bond scission and oxidation. Here, we report 11 metabolites of ART for the first time. The metabolic pathways and plausible structures were proposed according to accurate mass measurements and its MS/MS data. The present study comprehensively reports the in vitro and in vivo metabolism of ART mentioning 11 novel metabolites. Here, extensive use of HILIC has helped to efficiently separate various metabolites. These findings would help prospects of ART disposition and its congeners.

Selective quantitation of the neurotoxin BMAA by use of hydrophilic-interaction liquid chromatography-differential mobility spectrometry-tandem mass spectrometry (HILIC-DMS-MS/MS).

The neurotoxin β-N-methylamino-L-alanine (BMAA) has been reported in cyanobacteria and shellfish, raising concerns about widespread human exposure. However, inconsistent results for BMAA analysis have led to controversy. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the most appropriate method for analysis of BMAA, but the risk of interference from isomers, other sample components, and the electrospray background is still present. We have investigated differential mobility spectrometry (DMS) as an ion filter to improve selectivity in the hydrophilic interaction liquid chromatographic (HILIC)-MS/MS determination of BMAA. We obtained standards for two BMAA isomers not previously analyzed by HILIC-MS, β-amino-N-methylalanine and 3,4-diaminobutanoic acid, and the typically used 2,4-diaminobutanoic acid and N-(2-aminoethyl)glycine. DMS separation of BMAA from these isomers was achieved and optimized conditions were used to develop a sensitive and highly selective multidimensional HILIC-DMS-MS/MS method. This work revealed current technical limitations of DMS for trace quantitation, and practical solutions were implemented. Accurate control of low levels of DMS carrier gas modifier was essential, but required external metering. The linearity of our optimized method was excellent from 0.01 to 6 μmol L(-1). The instrumental LOD was 0.4 pg BMAA injected on-column and the estimated method LOD was 20 ng g(-1) dry weight for BMAA in sample matrix. The method was used to analyze cycad plant tissue, a cyanobacterial reference material, and mussel tissues, by use of isotope-dilution quantitation with deuterated BMAA. This confirmed the presence of BMAA and several of its isomers in cycad and mussel tissues, including commercially available mussel tissue reference materials certified for other biotoxins. Graphical Abstract Differential Mobility Spectrometry is used to increases the selectivity of BMAA analysis by HILIC-MS/MS.

Evaluating the use of HILIC in large-scale, multi dimensional proteomics: Horses for courses?

Despite many recent advances in instrumentation, the sheer complexity of biological samples remains a major challenge in large-scale proteomics experiments, reflecting both the large number of protein isoforms and the wide dynamic range of their expression levels. However, while the dynamic range of expression levels for different components of the proteome is estimated to be ∼107–8, the equivalent dynamic range of LC–MS is currently limited to ∼106. Sample pre-fractionation has therefore become routinely used in large-scale proteomics to reduce sample complexity during MS analysis and thus alleviate the problem of ion suppression and undersampling. There is currently a wide range of chromatographic techniques that can be applied as a first dimension separation. Here, we systematically evaluated the use of hydrophilic interaction liquid chromatography (HILIC), in comparison with hSAX, as a first dimension for peptide fractionation in a bottom-up proteomics workflow. The data indicate that in addition to its role as a useful pre-enrichment method for PTM analysis, HILIC can provide a robust, orthogonal and high-resolution method for increasing the depth of proteome coverage in large-scale proteomics experiments. The data also indicate that the choice of using either HILIC, hSAX, or other methods, is best made taking into account the specific types of biological analyses being performed.

Book Review: Hydrophilic Interaction Liquid Chromatography (HILIC) and Advanced Applications

Book Review: Hydrophilic Interaction Liquid Chromatography (HILIC) and Advanced Applications