Evaluation of microextraction by packed sorbent, liquid–liquid microextraction and derivatization pretreatment of diet‐derived phenolic acids in plasma by gas chromatography with triple quadrupole mass spectrometry

Abstract

Miniaturized sample pretreatments for the analysis of phenolic metabolites in plasma, involving protein precipitation, enzymatic deconjugation, extraction procedures, and different derivatization reactions were systematically evaluated. The analyses were conducted by gas chromatography with mass spectrometry for the evaluation of 40 diet-derived phenolic compounds. Enzyme purification was necessary for the phenolic deconjugation before extraction. Trimethylsilanization reagent and two different tetrabutylammonium salts for derivatization reactions were compared. The optimum reaction conditions were 50 μL of trimethylsilanization reagent at 90°C for 30 min, while tetrabutylammonium salts were associated with loss of sensitivity due to rapid activation of the inert gas chromatograph liner. Phenolic acids extractions from plasma were optimized. Optimal microextraction by packed sorbent performance was achieved using an octadecylsilyl packed bed and better recoveries for less polar compounds, such as methoxylated derivatives, were observed. Despite the low recovery for many analytes, repeatability using an automated extraction procedure in the gas chromatograph inlet was 2.5%. Instead, using liquid-liquid microextraction, better recoveries (80-110%) for all analytes were observed at the expense of repeatability (3.8-18.4%). The phenolic compounds in gerbil plasma samples, collected before and 4 h after the administration of a calafate extract, were analyzed with the optimized methodology.

Targeted analysis of microbial-generated phenolic acid metabolites derived from grape flavanols by gas chromatography-triple quadrupole mass spectrometry

“…This study used GC-TOF/MS without targeted analysis in MRM mode, which could explain the much lower sensitivity. In a recent investigation closer to the present work, a GC-QqQ/MS method was established for the analysis of phenolic acid metabolites in plasma samples from gerbils administered with a berry ( Barneris microphylla ) extract [12]. Comparable LLOQs were reported, ranging from 0.5 to 16.9 ng/mL when a liquid-liquid extraction method was applied.…”

“…Regarding the derivatization reagent, trimethylsilyl (TMS) derived reagents including trimethylsilyl chloride (TMCS) have been successfully applied to the analysis of polyphenol-derived metabolites in plasma and other biological matrices [12,21,24]. In our study, HMDS-TMCS-pyridine (3:1:9, v /v /v) was used due to its feasibility to silyate weakly acidic polar compounds, whereas no validation study has been conducted to evaluate the efficacy of the derivatization.…”

“…Although a number of LC-MS/MS methods have been reported [18–20], there are limited GC-MS/MS methods for the analysis of diet-derived microbial phenolic metabolites [12]. In the present work, we report a highly sensitive and reproducible GC-QqQ/MS method for the identification and quantification of 16 microbial-derived phenolic acid metabolites, along with two grape polyphenol precursors, C and EC.…”

“…Analytical methods for the analysis of phenolic acid metabolites need to have high sensitivity and selectivity in view of the low concentrations of certain microbial-derived metabolites and the complex endogenous nature of biological matrices [12]. Polyphenol metabolites produced by microbial metabolism consist of mainly low molecular weight phenolic acids, generally comprised of hydroxybenzoic and hydroxycinnamic acids and their derivatives [6].…”

Determination of urinary methylhippuric acids using MIL‐53‐NH2 (Al) metal–organic framework in microextraction by packed sorbent followed by HPLC–UV analysis

“…Thus far, several sample preparation techniques like conventional liquid-liquid extraction (LLE) (National Institute for Occupational Safety and Health, 2003), solid-phase extraction (SPE) (Marchese, Curini, Gentili, Perret, & Rocca, 2004), hollow fiber-liquid-phase microextraction (HF-LPME) (Ghamari, Bahrami, Yamini, Shahna, & Moghimbeigi, 2017), and dispersive assisted-solid phase microextraction (Behbahani, Bagheri, Omidi, & Amini, 2018) have been used to analyze MHAs in the urine of exposed people. However, the applications of LLE have several drawbacks, including requiring a high volume of sample, complicated sample preparation, multistep procedures, toxic organic solvents (in some cases they are expensive, produce large quantities of secondary wastes and cause environmental pollution), laboriousness and providing low pre-concentration (Bustamante et al, 2017;Golfinopoulos, Lekkas, & Nikolaou, 2001).…”