Simultaneous determination of ethyl carbamate and 4-(5-)methylimidazole in yellow rice wine and soy sauce by gas chromatography with mass spectrometry

Abstract

We developed a new method, based on alkaline diatomite solid-phase extraction followed by gas chromatography with mass spectrometry, for the simultaneous determination of the toxic contaminants ethyl carbamate (EC) and 4-(5-)methylimidazole (4-MEI) in yellow rice wine and soy sauce. The optimal extraction conditions were defined. With the application of alkaline diatomite solid-phase extraction, damage to the capillary column by organic acids was greatly reduced. With deuterated EC used as the internal standard, the linearity of the calibration curves for EC and 4-MEI was good with correlation coefficient above 0.99. In a spiked experiment with EC and 4-MEI in yellow rice wine and soy sauce, recovery of the added EC was 80.5-102.5% and that of 4-MEI was 78.3-92.8%. The limit of quantification and limit of detection for EC were 6.0 and 2.0 μg/kg, respectively, and for 4-MEI were 15.0 and 5.0 μg/kg, respectively. The validation results demonstrate that the method is fast, simple, and selective, and therefore is suitable for simultaneously determining the presence of EC and 4-MEI in fermented food.

Simple and Fast Sample Preparation Followed by Gas Chromatography‐Tandem Mass Spectrometry (GC‐MS/MS) for the Analysis of 2‐ and 4‐Methylimidazole in Cola and Dark Beer

“…To our knowledge, the difference in 4‐MeI contents in cola obtained from fast food restaurants and bottled and canned colas from markets has never been reported previously. Our data were in good agreement with the previously reported values of 4‐MeI (94 to 325 μg/L) in cola in Korean markets as determined by headspace‐solid phase microextraction‐GC‐mass spectrometry (HS‐SPME‐GC‐MS) (Wu and others ). It is also interesting to note that the ranges of 4‐MeI contents in colas were similar, regardless of the countries.…”

“…Analytical methods of gas‐liquid chromatography (GC), reversed‐phase chromatography (HPLC), or capillary isotachophoresis have been introduced for the analysis of 2‐ and 4‐MeI. Gas chromatography–mass spectrometry (GC–MS), liquid chromatography–mass spectrometry (LC–MS), and LC‐tandem mass spectrometry (LC–MS/MS) are the most common techniques for the analysis of MeI in foods (Hengel and Shibamoto ; Schlee and others ; Wu and others ). Direct GC‐MS in selective ion monitoring (SIM) mode without derivatization is not sensitive enough for the quantification of 4‐MeI due to its low volatility and high polarity (Lim and Shin ).…”

Occurrence of Ethyl Carbamate in Foods and Beverages: Review of the Formation Mechanisms, Advances in Analytical Methods, and Mitigation Strategies

“…SPE can significantly reduce matrix interferences; some authors have reported detection of EC at the nanograms per liter (parts per trillion) concentration when samples are analyzed with GC-MS (37). However, the lengthy extraction procedure for EC analysis by GC-MS has encouraged researchers to develop methods that reduce sample preparation times (144,149,208).…”

Determination of Ten Plant Growth Regulators in Bean Sprouts by Mixed Solid Phase Extraction Columns Separation and LC-MS/MS

“…PGRs are often added during the bean sprout cultivation process to accelerate growth or improve the quality and quantity of the products. However, PGRs such as gibberellin A3 (GA 3 ), 2,4-dichlorophenoxy acetic acid (2,4-D), 4-chlorophenoxyacetic acid (4-CPA), indole-2-acetic acid (IAA), indole-3-butyric acid (IBA), forchlorfenuron (FCF), thidiazuron (TDZ), 6-benzyl adenine (6-BA), paclobutrazol (PBZ), and 6-furfurylaminopurine (6-KT) are forbidden for use in bean sprout production [2,4,5]. Nevertheless, reports of illegal PGR addition, such as through the application of "AB powder" (A contains 6-BA, and B contains GA 3 ), appear frequently enough to cause concern [6].…”

“…Several methods have been developed for analyzing the presence of PGRs in food samples, including GC [10,11], HPLC [12][13][14][15][16][17][18], GC-MS [5,19,20], electrochemical sensing method [21], and HPLC-MS [22][23][24][25][26][27]. The GC, HPLC, and GC-MS methods are often utilized, but some of these methods showed the complexity of samples pre-treatment and the low sensitivity of the detection results.…”