Quantitative high-performance liquid chromatographic determination of acrolein in plasma after derivatization with Luminarin 3

Fast and sensitive detection of acrolein in environmental water samples without derivatization using liquid chromatography tandem mass spectrometry

A fast and sensitive SPE-LC-MS/MS method for the determination of acrolein in environmental water samples using activated charcoal as SPE adsorbent was developed. The novelty of this study consists in acrolein extraction, separation and detection without the need of a derivatization process. Physicochemical properties of acrolein, such as low molecular weight and high polarity represent real challenges for extraction, separation, and detection of this pollutant using SPE-LC-MS/MS. These were addressed by choosing a suitable chromatographic column which ensures a good peak symmetry and retention for the analyte, as well as the choice of SPE adsorbent suitable for retaining very polar compounds like acrolein from the aqueous matrix. The chromatographic column was a Synergi Fusion RP (150 × 2.0 mm, 4.0 μm) with a C18 stationary phase modified with polar embedded amide groups. Activated charcoal adsorbent used as SPE extraction media was able to extract efficiently highly polar molecules such as acrolein and ¹³C₃-acrylamide (internal standard) from water samples. Using this method, the obtained extraction recovery for acrolein was 88% at a 50 ng/L concentration level. Overall method quantitation limit (LOQ) for acrolein in water was established at 3.8 ng/L. The newly developed SPE-LC-MS/MS method was successfully applied to detect acrolein occurrence in wastewater and drinking water samples. Acrolein level in these samples ranged from LOQ to 122 ng/L.

Bioanalytical and Mass Spectrometric Methods for Aldehyde Profiling in Biological Fluids

Human exposure to aldehydes is implicated in multiple diseases including diabetes, cardiovascular diseases, neurodegenerative disorders (i.e., Alzheimer’s and Parkinson’s Diseases), and cancer. Because these compounds are strong electrophiles, they can react with nucleophilic sites in DNA and proteins to form reversible and irreversible modifications. These modifications, if not eliminated or repaired, can lead to alteration in cellular homeostasis, cell death and ultimately contribute to disease pathogenesis. This review provides an overview of the current knowledge of the methods and applications of aldehyde exposure measurements, with a particular focus on bioanalytical and mass spectrometric techniques, including recent advances in mass spectrometry (MS)-based profiling methods for identifying potential biomarkers of aldehyde exposure. We discuss the various derivatization reagents used to capture small polar aldehydes and methods to quantify these compounds in biological matrices. In addition, we present emerging mass spectrometry-based methods, which use high-resolution accurate mass (HR/AM) analysis for characterizing carbonyl compounds and their potential applications in molecular epidemiology studies. With the availability of diverse bioanalytical methods presented here including simple and rapid techniques allowing remote monitoring of aldehydes, real-time imaging of aldehydic load in cells, advances in MS instrumentation, high performance chromatographic separation, and improved bioinformatics tools, the data acquired enable increased sensitivity for identifying specific aldehydes and new biomarkers of aldehyde exposure. Finally, the combination of these techniques with exciting new methods for single cell analysis provides the potential for detection and profiling of aldehydes at a cellular level, opening up the opportunity to minutely dissect their roles and biological consequences in cellular metabolism and diseases pathogenesis.

Lipoxidation in cardiovascular diseases

Lipids can go through lipid peroxidation, an endogenous chain reaction that consists in the oxidative degradation of lipids leading to the generation of a wide variety of highly reactive carbonyl species (RCS), such as short-chain carbonyl derivatives and oxidized truncated phospholipids. RCS exert a wide range of biological effects due to their ability to interact and covalently bind to nucleophilic groups on other macromolecules, such as nucleic acids, phospholipids, and proteins, forming reversible and/or irreversible modifications and generating the so-called advanced lipoxidation end-products (ALEs). Lipoxidation plays a relevant role in the onset of cardiovascular diseases (CVD), mainly in the atherosclerosis-based diseases in which oxidized lipids and their adducts have been extensively characterized and associated with several processes responsible for the onset and development of atherosclerosis, such as endothelial dysfunction and inflammation. Herein we will review the current knowledge on the sources of lipids that undergo oxidation in the context of cardiovascular diseases, both from the bloodstream and tissues, and the methods for detection, characterization, and quantitation of their oxidative products and protein adducts. Moreover, lipoxidation and ALEs have been associated with many oxidative-based diseases, including CVD, not only as potential biomarkers but also as therapeutic targets. Indeed, several therapeutic strategies, acting at different levels of the ALEs cascade, have been proposed, essentially blocking ALEs formation, but also their catabolism or the resulting biological responses they induce. However, a deeper understanding of the mechanisms of formation and targets of ALEs could expand the available therapeutic strategies.

Determination of acrolein in serum by high-performance liquid chromatography with fluorescence detection after pre-column fluorogenic derivatization using 1,2-diamino-4,5-dimethoxybenzene

Acrolein is a major unsaturated aldehyde that is generated during the lipid peroxidation process. The measurement of acrolein in biological samples should be useful to estimate the degree of lipid peroxidation and to evaluate the effect of hazardous properties of acrolein on human health. In this study, a highly sensitive and selective high-performance liquid chromatography with fluorescence detection method was developed for the determination of acrolein in human serum. The proposed method involves the pre-column fluorogenic derivatization of acrolein with 1,2-diamino-4,5-dimethoxybenzene (DDB) as a reagent. The fluorescent derivative of acrolein could be detected clearly without any interfering reagent blank peaks because DDB does not have intrinsic fluorescence itself, and the detection limit was 10 nM (signal-to-noise ratio = 3). The proposed method could selectively detect acrolein in human serum with a simple protein precipitation treatment.

Isotope-labeling studies on the formation pathway of acrolein during heat processing of oils

Acrolein (2-propenal) is classified as a foodborne toxicant and was shown to be present in significant amounts in heated edible oils. Up to now, its formation was mainly suggested to be from the glycerol part of triacylglycerides, although a clear influence of the unsaturation of the fatty acid moiety was also obvious in previous studies. To unequivocally clarify the role of the glycerol and the fatty acid parts in acrolein formation, two series of labeled triacylglycerides were synthesized: [(13)C(3)]-triacylglycerides of stearic, oleic, linoleic, and linolenic acid and [(13)C(54)]-triacylglycerides with labeled stearic, oleic, and linoleic acid, but with unlabeled glycerol. Heating of each of the seven intermediates singly in silicon oil and measurement of the formed amounts of labeled and unlabeled acrolein clearly proved the fatty acid backbone as the key precursor structure. Enzymatically synthesized pure linoleic acid and linolenic acid hydroperoxides were shown to be the key intermediates in acrolein formation, thus allowing the discussion of a radical-induced reaction pathway leading to the formation of the aldehyde. Surprisingly, although several oils contained high amounts of acrolein after heating, deep-fried foods themselves, such as donuts or French fries, were low in the aldehyde.

Analytical method for lipoperoxidation relevant reactive aldehydes in human sera by high-performance liquid chromatography-fluorescence detection

A validated, simple and sensitive HPLC method was developed for the simultaneous determination of lipoperoxidation relevant reactive aldehydes: glyoxal (GO), acrolein (ACR), malondialdehyde (MDA), and 4-hydroxy-2-nonenal (HNE) in human serum. The studied aldehydes were reacted with 2,2'-furil to form fluorescent difurylimidazole derivatives that were separated on a C18 column using gradient elution and fluorescence detection at excitation and emission wavelengths of 250 and 355nm, respectively. The method showed good linearity over the concentration ranges of 0.100-5.00, 0.200-10.0, 0.200-40.0, and 0.400-10.0nmol/mL for GO, ACR, HNE, and MDA, respectively, with detection limits ranging from 0.030 to 0.11nmol/mL. The percentage RSD of intraday and interday precision did not exceed 5.0 and 6.2%, respectively, and the accuracy (%found) ranged from 95.5 to 103%. The proposed method was applied for monitoring the four aldehydes in sera of healthy, diabetic, and rheumatic human subjects with simple pretreatment steps and without interference from endogenous components. By virtue of its high sensitivity and accuracy, our method enabled detection of differences between analytes concentrations in sera of human subjects under different clinical conditions.

Determination of acrolein by high-voltage capillary electrophoresis from oxidized fatty acids

Acrolein is an alpha,beta-unsaturated aldehyde with enormous capacity of reaction, occurs in the air like a pollutant, but it is (we know now) an important lipid peroxidation product as well. The compound is one of the several aldehydes produced from fatty acid oxidation, although it is particularly important because it constitutes the major electrophyle aldehyde derived from lipid oxidation. Acrolein can be formed actively from oxidized fatty acids and undergo aldolic condensation in alkaline pH; this is a particular characteristic that we have used in its process of separation with capillary electrophoresis. We have shown that the oxidation of unsaturated fatty acids forms acrolein, and that the use of capillary electrophoresis to be a powerful, sensitive, and attractive method for separation, identification, and quantization of this and other aldehydes from in vitro lipid peroxidation.

A generic approach for the determination of residues of alkylating agents in active pharmaceutical ingredients by in situ derivatization–headspace–gas chromatography–mass spectrometry

A simple, reliable and fast procedure for the simultaneous determination of residues of some common alkylating agents (AAs), such as mesylates, besylates, tosylates and sulfates, employed in drug synthesis, has been developed by in situ derivatization-headspace-gas chromatography-mass spectrometry. Pentafluorothiophenol is used as a derivatizing agent in different water/dimethyl sulfoxide ratios. Compared to former analytical procedures, this approach returns improvements in analysis time, selectivity, analyte stability and method sensitivity (LOD=0.11 microgg(-1) for methyl tosylate). The method exhibits low matrix dependence, excellent accuracy, precision (R.S.D.=2.8-10% range at 1 microgg(-1)) and robustness through the use of deuterated internal standards. Knowledge of the synthetic route allows a targeted approach to the determination of specific AAs since the procedure does not distinguish between acid species. The procedure was successfully applied to different pharmaceutical matrixes, and is particularly suitable for routine analysis with high sample throughput.

Quantitative analysis of acrolein in heated vegetable oils by liquid chromatography with pulsed electrochemical detection

A sensitive and selective analytical method for the determination of acrolein in heated vegetable oils by liquid chromatographic separation with pulsed electrochemical detection is described. An optimized triple-step pulsed waveform, based on the formation/inhibition of PtOH species on the electrode surface, a consequence of the absence/presence of adsorbing analytes, is described for the sensitive detection of acrolein in acidic medium. Under these optimized experimental conditions the proposed analytical method allowed detection limits of 0.15 microM without pre- or postcolumn derivatization or tedious cleanup procedures. The proposed analytical method was successfully employed for the sensitive determination of acrolein in fresh and heated vegetable oils with good mean recoveries, selectivity, and analytical reproducibility.

Separation methods for alkylating antineoplastic compounds

The separating method for alkylating neoplastic compounds were reviewed based on the classification of the Merck Index (12th Edition). Each section, whenever available or relevant, was subdivided according to the following approach: stability studies, extraction methods, gas chromatography, high-performance liquid chromatography and capillary electrophoresis. At the end of each chapter a separate table summarizing the main characteristics of the separating method were established. In particular LODs and/or LOQs were expressed as quantity to facilitate comparison between methods. This review highlights the problems to measure trace levels of these compounds into biological fluids with respect to their instability, adsorption to glass and plastic or derivatization requirements. Over the last decades, HPLC seems to be more popular than GC for separating the alkylating agents. The development of narrow- or microbore LC coupled to MS is certainly the way to further improve both separation and sensitivity obtained in the different papers surveyed for this review.

Cyclophosphamide and related anticancer drugs

This article presents an overview of the methods of bioanalysis of oxazaphosphorines, in particular, cyclophosphamide, ifosfamide, and trofosfamide as well as their metabolites. The metabolism of oxazaphosphorines is complex and leads to a large variety of metabolites and therefore the spectrum of methods used is relatively broad. The various methods used are shown in a table and the particularly important assays are described.