4-hydrazinobenzoic acid as a derivatizing agent for aldehyde analysis by HPLC-UV and CE-DAD

Abstract

Aldehydes are relevant analytes in a wide range of samples, in particular, food and beverages but also body fluids. Hydrazines can undergo nucleophilic addition with aldehydes or ketones giving origin to hydrazones (a group of stable imines) that can be suitably used in the identification of aldehydes. Herein, 4-hydrazinobenzoic acid (HBA) was, for the first time, used as the derivatizing agent in analytical methodologies using liquid chromatography aiming the determination of low-molecular aldehydes. The derivatization reaction was simultaneously performed along with the extraction process, using gas-diffusion microextraction (GDME), which resulted in a clean extract containing the HBA-aldehyde derivates. The corresponding formed imines were determined by both high-performance liquid chromatography (LC) with UV spectrophotometric detection (HPLC-UV) and capillary electrophoresis with diode array detection (CE-DAD). HBA showed to be a rather advantageous derivatization reagent due to its stability, relatively high solubility in water and other solvents, high selectivity and sensibility, reduced impurities, simple preparation steps and applicability to different separation and/or different detection techniques. Limits of detections (LODs) of the optimized methodologies (in terms of time and pH among other experimental variables) were all below 0.5 mg L, using both instrumental techniques. Furthermore, for the first time, the HBA-aldehyde derivatives were analyzed by LC with mass spectrometry (LC-MS), demonstrating the possibility of identification by MS of each compound. The developed methodologies were also successfully applied in the analysis of formaldehyde and acetaldehyde in several alcoholic beverages. This was also the first time GDME was combined with CE, showing that it can be a valuable sample preparation tool for electrophoresis, in particular by eliminating the interference of ions and inorganic constituents present in the samples.

Cyclohexane‐1,3‐dione as a derivatizing agent for the analysis of aldehydes by micelar electrokinetic chromatography with diode array detection

“…CHD was compared with other two derivatizing agents, MBTH and PHSA. The reactions between MBTH and PHSA occur in a similar manner, aldehydes react with the amine group forming imines . Since the aldehyde‐CHD adducts are electrically neutral compounds, the separation would be successfully performed using MEKC.…”

“…Derivatization, with all its advantages , has been widely employed in aldehyde analysis to overcome the aforementioned challenges. Several derivatizing reagents have been applied in a variety of matrices, and with many different instrumental techniques . The most widely used derivatizing agent is likely to be 2,4‐dinitrophenylhydrazine, typically combined with instrumental analysis by high‐performance liquid chromatography with UV detection (HPLC‐UV) .…”

Bioanalytical and Mass Spectrometric Methods for Aldehyde Profiling in Biological Fluids

“…DNPH derivatization and HPLC-UV analysis are used in environmental monitoring of air and water quality and used for screening and monitoring carbonyl compounds in various matrices by the US federal agencies (Table 1) [119,133,134,135,136,137]. The HPLC-UV technique is also being used in the food industry to measure aldehydes in food and beverages [39,138,139,140,141,142] and in biomedical research to measure aldehydes and carbonyls in various matrices such as urine, plasma and serum samples [40,143,144,145,146,147,148,149,150,151,152]. DNPH derivatization is also used in conjunction with a reducing agent, 2-picoline borane (2-PB) to stabilize carbonyl-hydrazones and to resolve isomeric compounds produced during the reaction that might interfere with subsequent quantitative analysis by HPLC-UV [153].…”

Salting‐out assisted liquid–liquid extraction with dansyl chloride for the determination of biogenic amines in food

“…Since most BAs lack a chromophore group, a derivatisation step was also required prior to the analyses to improve their sensitivity to UV and FD (Valente et al, 2012;€ Onal et al, 2013;Jain et al, 2015;Mohammed et al, 2016). Derivatisation is a chemical modification of the analyte that serves several purposes, not only it can make an analyte 'visible' to a specific instrumental technique but it can also enhance sensitivity as well as selectivity (Gonc ßalves et al, 2010a(Gonc ßalves et al, ,2010b(Gonc ßalves et al, , 2017Pacheco et al, 2010;Ramos et al, 2012;de Lima et al, 2018). DNS-Cl is a suitable derivatising agent since it produces stable derivatives which are detected by both UV and FD (Jia et al, 2011;Bu nka et al, 2012;Romano et al, 2012;Ord oñez et al, 2016).…”