دانلود رایگان مقاله انگلیسی تعیین ۴-متیل‌ایمیدازول در کم خونی کاراملی با استفاده از گاز کروماتوگرافی - هینداوی 2018

One of Maillard reaction products formed in the production of ammonia caramel is 4(5)-methylimidazole (4-MeI) classifed as carcinogen. A method of 4-MeI determination based on ion-pair extraction and derivatisation with isobutyl chloroformate with subsequent gas chromatography-tandem mass spectrometry analysis was proposed. Tandem mass spectrometry was applied to reduce the infuence of matrix and increase the selectivity and sensitivity of the method. Triple quadrupole GC-MS system was used for this study. Te collision energies were optimized for MRM mode. Te detection (LOD) and quantifcation limits (LOQ) of the elaborated method were 17 and 37.8 �g kg−1, respectively, repeatability was <15% RSD for analyzed caramel samples, and the recovery for 4-MeI was 101%. Comparison of MS/MS with SIM detection on the same instrument proved almost 30 times lower LODs achieved by tandem mass spectrometry compared to SIM. Described method can be routinely used for monitoring 4-MeI as a quality and safety marker in the production of ammonia caramel.

4. Conclusion

Described method, based on ion pairing and derivatization in sample preparation steps, followed by gas chromatography with tandem mass spectrometry was useful for determination of 4-MeI in highly complex matrix, which is ammonia caramel. As the matrix contains numerous compounds that may interfere with 4-MeI, selective extraction, derivatization, and detection were required. Te novelty of this study was the use of MS/MS for quantitation of 4-MeI. As tandem mass spectrometry virtually eliminates the infuence of matrix, especially coelution of ions of the same �/�, (as may happen in SIM), by their subsequent fragmentation, it allows more reliable quantitation and improved s/n ratio. Te method proved to be more sensitive than SIM (determined on the same instrument, approximately 30 times) and was successfully applied to control levels of 4-MeI in ammonia caramel.