Dispersive liquid–liquid microextraction with in situ derivatization coupled with gas chromatography and mass spectrometry for the determination of 4‐methylimidazole in red ginseng products containing caramel colors

Abstract

A rapid analytical method was developed for the determination of 4-methylimidazole from red ginseng products containing caramel colors by using dispersive liquid-liquid microextraction with in situ derivatization followed by gas chromatography with mass spectrometry. Chloroform and acetonitrile were selected as the extraction and dispersive solvents, and based on the extraction efficiency, their optimum volumes were 200 and 100 μL, respectively. The optimum volumes of the derivatizing agent (isobutyl chloroformate) and catalyst (pyridine), pH, and concentration of NaCl in the sample solution were determined to be 25 and 100 μL, pH 7.6, and 0% w/v, respectively. Validation of the optimized method showed good linearity (R > 0.999), accuracy (≥89.86%), intra- (≤6.70%) and interday (≤4.17%) repeatability, limit of detection (0.96 μg/L), and limit of quantification (5.79 μg/L). The validated method was applied to quantify 4-methylimidazole in red ginseng juices and concentrates, 4-methylimidazole was only found in red ginseng juices containing caramel colorant (42.91-2863.4 μg/L) and detected in red ginseng concentrates containing >1% caramel colorant.

Separation and quantification of imidazoles in atmospheric particles using LC–Orbitrap‐MS

“…To accomplish this task methods enabling a fast analysis with minimal sample preparation to determine imidazoles in aerosol particles are favourable. In the literature, besides one method to determine imidazoles in atmospheric particles , other methods exist to determine low molecular weight imidazoles in matrices like food and beverages . Imidazoles of higher molecular weight (>250 Da) are often used as pharmaceutics and have recently been found in environmental waters .…”

Advances and challenges in ginseng research from 2011 to 2020: the phytochemistry, quality control, metabolism, and biosynthesis

“…Ginsenosides represent a group of high- to medium-polarity triterpenoids, enabling high extraction efficiency from the raw materials by protonic solvents. An overall summary of the extraction methods targeting saponins was conducted 19–53 in terms of extraction efficiency, operability, extraction speed, and the degree of automation (Table 1).…”

“…Saponins, mixed with the other components in the total extracts, can be further fractionated, enriched, and purified with the aid of liquid–liquid separation ( e.g. dispersive liquid–liquid microextraction, DLLME; liquid–liquid extraction, LLE), 44–48 solid-phase extraction (SPE), 49,50 and supercritical fluid extraction (SFE). 51…”

Determination of vitamin K encapsulated into lipid nanocarriers by dispersive liquid–liquid microextraction combined with liquid chromatography–atmospheric pressure chemical ionization–tandem mass spectrometry

“…In particular, dispersive liquid–liquid microextraction (DLLME, first reported in 2006; Rezaee et al, 2006 ) offers the advantages of high accuracy, low solvent consumption, short extraction time, and high enrichment factors (Viñas et al, 2014 ) and has been successfully used to extract highly and moderately lipophilic compounds like aromatic amines, polycyclic aromatic hydrocarbons, and pesticide residues (Andraščíková et al, 2013 ; Galuch et al, 2019 ; Liu et al, 2014 ; Özkan et al, 2019 ). In DLLME, the analyte is transferred from the aqueous phase (sample solution) to the organic phase (extraction solvent) with the help of a dispersive solvent, which reduces the polarity of the aqueous phase and increases the solubility of the target analyte in the organic phase (Farajzadeh et al, 2016 ; Lee et al, 2018 , 2019 ).…”