Development of a Mixed Solution Certified Reference Material of Vanillin Spices

Well-characterized solution certified reference materials (CRMs) are necessary for the accurate determination, quality control, instrument calibration, and validation of analytical approach. Simultaneously, a mixed solution CRM of vanillin spices is in high demand because of the accurate measurement and traceability of vanillin spices in various food matrices. In this study, a mixed vanillin spices acetonitrile CRM (issued with GBWE 086557), including methylvanillin, ethylvanillin, vanillin, and coumarin, has been developed using the gravimetric method by the National Institute of Metrology, China. Methylvanillin, ethylvanillin, and vanillin showed poor stability in methanol. The acetalization of the aldehyde group of vanillin was the major step during the degradation process, as elucidated by ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), and exposure to high temperature and light irradiation accelerated the degradation dramatically, whereas the acetonitrile CRMs held sufficient homogeneity, and they were stored stable at 4 °C over 9 months or 50 °C for 7 days. Typically, the certified values for methylvanillin, ethylvanillin, vanillin, and coumarin in CRM were 10.1 ± 0.2, 10.2 ± 0.2, 10.0 ± 0.3, and 10.0 ± 0.2 μg/mL (k = 2), respectively.