Justyna Walczak

Pharmacokinetic study of amoxicillin in human plasma by solid-phase microextraction followed by high-performance liquid chromatography-triple quadrupole mass spectrometry.

Sensitive and selective analytical procedures based on high-performance liquid chromatography with mass spectrometric detection were developed for the determination of amoxicillin in human plasma samples. Samples were prepared by applying in-house manufactured molecularly imprinted solid-phase microextraction probes. The detection of target compounds was performed in multiple reaction monitoring mode. The multiple reaction monitoring detection was operated in the positive electrospray ionization mode using the transitions of m/z 366 ([M + H](+) ) → 349 for amoxicillin and m/z 390 ([M + H](+) ) → 372 for gemifloxacin. The method was validated with precision within 15% relative standard deviation and accuracy within 15% relative error. The method was successfully applied to study of the pharmacokinetics of amoxicillin in human plasma after oral administration of amoxicillin.

Two-Dimensional High Performance Liquid Chromatography-Mass Spectrometry for Phosphatidylcholine Analysis in Egg Yolk

Phospholipids are one of the classes of lipids, which are a major component of all cell membranes. Phosphatidylcholine (PC) is the main phospholipid present in egg yolk. The phospholipids extract from enriched egg yolk was separated using the two-dimensional high performance liquid chromatography in off-line system coupled with electrospray ionization tandem mass spectrometry (off-line HPLC-ESI-MS/MS). In the first dimension, a preparative C18 column was used, and on the second dimension, a separation was performed on N,O-dialkylphosphoramidate bonded silica column. In the analyzed egg yolk, 15 different phosphatidylcholines was found. From among the identified fatty acid of PC, a large part constitutes docosahexaenoic acid (ω-3, 22:6, DHA) and linoleic acid (ω-6, 18:2, LA).

Determination of phospholipids in milk using a new phosphodiester stationary phase by liquid chromatography-matrix assisted desorption ionization mass spectrometry

A methodology employing high performance liquid chromatography coupled with matrix-assisted laser desorption and ionization time-of-flight mass spectrometry has been utilized to determine the quality of phospholipid classes. Home-made phosphoester chemically bonded stationary phase containing diol, phosphate and octadecyl groups (Diol-P-C18) has been employed in the separation of polar lipids from milk. Each phospholipid fraction was collected manually and identified by MALDI-TOF MS.

Analytical Techniques in Lipidomics: State of the Art

ABSTRACT Current studies related to lipid identification and determination, or lipidomics in biological samples, are one of the most important issues in modern bioanalytical chemistry. There are many articles dedicated to specific analytical strategies used in lipidomics in various kinds of biological samples. However, in such literature, there is a lack of articles dedicated to a comprehensive review of the actual analytical methodologies used in lipidomics. The aim of this article is to characterize the lipidomics methods used in modern bioanalysis according to the methodological point of view: (1) chromatography/separation methods, (2) spectroscopic methods and (3) mass spectrometry and also hyphenated methods. In the first part, we discussed thin layer chromatography (TLC), high-pressure liquid chromatography (HPLC), gas chromatography (GC) and capillary electrophoresis (CE). The second part includes spectroscopic techniques such as Raman spectroscopy (RS), Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR). The third part is a synthetic review of mass spectrometry, matrix-assisted laser desorption/ionization (MALDI), hyphenated methods, which include liquid chromatography–mass spectrometry (LC-MS), gas chromatography–mass spectrometry (GC-MS) and also multidimensional techniques. Other aspects are the possibilities of the application of the described methods in lipidomics studies. Due to the fact that the exploration of new methods of lipidomics analysis and their applications in clinical and medical studies are still challenging for researchers working in life science, we hope that this review article will be very useful for readers.

HPLC separation of casein components on a diol-bonded silica column with MALDI TOF/TOF MS identification

A comparative study has been made of three home-made bonded silica columns for the separation of the components of bovine milk casein (α-, β- and κ-casein). A gradient elution HPLC procedure is now proposed for separation of the protein components, and the tests conducted have confirmed the superiority of columns based on diol-bonded silica over octadecyl- or amine-bonded silica. A matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometer (MALDI-TOF MS) has been utilized as a detector for off-line identification of the components of the casein fractions. The method selected enables effective and rapid separation of the casein components, together with their detailed MS characterization.

Comparison of Various Extraction Techniques of Medicago sativa: Yield, Antioxidant Activity, and Content of Phytochemical Constituents

Medicago sativa L. (M. sativa) is a source of many valuable secondary metabolites. Extraction yield and the concentration of phenolics, flavonoids, and saponins, as well as antioxidant potential were determined in extracts from different parts of M. sativa obtained using extraction methods such as maceration, ultrasound-assisted extraction (UAE), accelerated solvent extraction (ASE), and supercritical fluid extraction (SFE). The concentrations of the listed groups of compounds were spectrophotometrically determined and confirmed by HPLC-MS. The results showed that ASE of flowers with 70% ethanol (EtOH) provided the highest yield of extraction (47.5 ± 4.0%), whereas the lowest yield was obtained in stems (4.0 ± 0.2%). The 70% EtOH extract from flowers showed the highest phenolic content [48.4 ± 4.6 mg gallic acid equivalents/g dry matter (DM)], as well as the highest antioxidant activity. The highest total flavonoid content (139.0 ± 7.1 mg rutin equivalents/g DM) was observed in the extract from leaves obtained through SFE. This extract was also especially rich in saponins [622.2 ± 30.3 mg oleanolic acid equivalents (OAE)/g DM]. However, the lowest compound content was observed in maceration extracts from stems (54.6 ± 27.0 mg OAE/g DM). The results suggest that EtOH extracts from alfalfa flowers and SFE extracts from M. satvia leaves, especially, may serve as potential sources of natural antioxidants for nutraceuticals, food additives, and cosmetic ingredients.

Determination of Omega Fatty Acid Profiles in Egg Yolk by HILIC-LC-MS and GC-MS

The paper presents the analysis of the profile composition of fatty acids in the molecules of phosphatidylcholine and phosphatidylethanolamine, by using hydrophilic interaction liquid chromatography and gas chromatography coupled with mass spectrometry. The profiles of 15 phosphatidylcholine and 8 phosphatidylethanolamine species were analyzed with a newly developed hydrophilic interaction liquid chromatography (HILIC)–electrospray ionization (ESI)–tandem mass spectroscopy (MS/MS) method, by using a new stationary bonded phase. The application of the new method in control and experimental groups of egg yolk revealed significant differences in the composition of phospholipid species containing mainly polyunsaturated fatty acids. Additionally, using GC-MS, the profile of fatty acids in four groups with different dietary supplementation of hens was analyzed and 20 fatty acids in egg yolks were determined. Monounsaturated fatty acids were found in higher amounts than saturated fatty acids and polyunsaturated fatty acids in egg yolks. Oleic acid (18:1) was the major monounsaturated fatty acid in egg yolk while palmitic acid (16:0) was the major saturated fatty acid. Linoleic acid (18:2), arachidonic acid (20:4), and docosahexaenoic acid (22:6) reached the highest levels among the polyunsaturated fatty acids.

Non-target analysis of phospholipid and sphingolipid species in egg yolk using liquid chromatography/triple quadrupole tandem mass spectrometry

In this work, phospholipids extracted from egg yolk (control group, experimental group) were identified using high performance liquid chromatography coupled with electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). Combinations of fatty acyls occurring in 11 classes of phospholipids from egg yolk were investigated. Differences between the profile of fatty acyls from hens fed traditionally and the ones that received special diet supplementation were observed. Experimental findings were complemented with multivariate chemometric analysis. Multiple reaction monitoring mass spectrometry mode was utilized and 123 distinct combinations of fatty acyls occurring in phospholipids were identified. From these, large portions are polyunsaturated fatty acyls from the omega-3 and omega-6 family. HPLC MS/MS analysis allows for quick, accurate and precise determination of biologically active compounds, found in low concentrations within the tested material.

Silver nanoparticles functionalized with ampicillin

The resistance of pathogenic bacteria to antibiotics has become a serious problem. The emphasis is placed on the development of new, effective antimicrobial strategies. One of them is the use of AgNPs in association with antibiotic drugs. The aim of this study was to obtain silver nanoparticles functionalized with ampicillin and to investigate the mechanism of binding antibiotics to nanoparticle using high‐performance liquid chromatography approach. To confirm the occurrence of silver nanoparticles functionalization, FTIR, MALDI‐TOF MS, and DLS analysis and zeta potential measurements were performed. Moreover we assessed the antibacterial activity of biologically synthesized nanoparticles functionalized with ampicillin against a range of gram (+) and gram (−) bacteria strains such as Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus epidermidis, and Escherichia coli.

Microbiology neutralization of zearalenone using Lactococcus lactis and Bifidobacterium sp.

AbstractThe aim of the study was to neutralize zearalenone by lactic acid bacteria (LAB) such as Lactococcus lactis and Bifidobacterium sp. and investigate the mechanism of zearalenone (ZEA) binding. Neutralization of ZEA by LAB was confirmed by identification of binding kinetics and spectroscopic studies such as Fourier transform infrared spectroscopy (FT-IR) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The obtained results showed that the kinetic process of zearalenone binding to L. lactis is not homogeneous but is expressed with an initial rapid stage with about 90% of ZEA biosorption and with a much slower second step. In case of Bifidobacterium sp., the neutralization process is homogeneous; the main stage can be described with about 88% of ZEA biosorption. MALDI–TOF-MS measurements and FTIR analysis confirmed the uptake of zearalenone molecules by bacterial species. Moreover, the assessment of dead and live lactic acid bacteria cells after zearalenone treatment was performed using fluorescence microscopy. Graphical abstractMicrobiology neutralization of zearalenone using Lactococcus lactis and Bifidobacterium sp. was confirmed by identification of binding kinetics and spectroscopic studies such as FT-IR spectroscopy and MALDI-TOF-MS spectrometry. The mechanism of ZEA binding was also investigated.