UPLC-Q/Orbitrap-HRMS技术筛查及测定饮料中11种人工和天然甜味剂

Screening and Determination of 11 Types of Artificial and Natural Sweeteners in Beverages by UPLC-Q/Orbitrap-HRMS technology

摘要:

为了探究饮料中人工和天然甜味剂的添加状况，建立了超高效液相色谱-四极杆/静电场轨道阱高分辨质谱（UPLC-Q/Orbitrap HRMS）筛查和测定饮料中11种人工和天然甜味剂的方法，并对甜味剂的质谱裂解规律进行了解析。饮料样品经体积比1:1的甲醇-水溶液稀释，过滤膜后滤液经HSS T3色谱柱分离，UPLC-Q/Orbitrap HRMS检测。质谱同时采集一级母离子和二级碎片离子，以保留时间、母离子和二级碎片离子进行定性确证，母离子的峰面积进行定量。通过质谱裂解规律的解析，发现甜菊糖苷类甜味剂具有共性碎片离子m/z 641.316 3、479.265 0和317.211 9，通过母离子和共性碎片离子可实现对样品中未知甜菊糖苷类化合物的定性识别。方法学结果表明，11种甜味剂在相应浓度范围内线性关系良好，平均回收率为77.29%~98.82%，相对标准偏差为1.5%~9.6%（n=5），芦荟苷的方法检出限为150.0 μg/L，其他10种甜味剂的检出限为1.0~15.0 μg/L。实际样品检测发现2款果饮料中筛查出甜蜜素（质量浓度分别为0.8 mg/L和190.9 mg/L），1款茶饮料中筛查出甜菊糖苷和瑞鲍迪苷（质量浓度分别为94.2 μg/L和62.1 μg/L），未筛查出含有其他未知的甜菊糖苷类甜味剂。研究结果表明所测饮料中甜味剂的含量虽未超过标准规定的最大允许使用量，但存在标签内容不全的现象，应加强对食品标签的监督管理。

Abstract:

In order to explore the status of adding artificial and natural sweeteners to beverages, an ultra-high performance liquid chromatography-quadrupole/electrostatic orbitrap high-resolution mass spectrometry (UPLC-Q/Orbitrap HRMS) method was established for the screening and determination of 11 types of artificial and natural sweeteners in beverages, and the MS fragmentation pathways of the sweeteners were profiled. The beverage samples were diluted with a methanol-water solution in a volume ratio of 1:1, and after filtration through a membrane, the filtrate was separated using an HSS T3 column then detected by UPLC-Q/Orbitrap HRMS. Mass spectrometry simultaneously collected primary parent ions and secondary fragment ions for qualitative confirmation based on the retention time, parent ion and secondary fragment ions, while the peak areas of the parent ions were used for quantification. Through profiling of the MS fragment pathways, it was found that the steviol glycosides had common fragment ions m/z 641.316 3, 479.265 0 and 317.211 9, allowing for qualitative identification of the unknown steviol glycoside compounds in the samples using the parent ion and common fragment ions. The method validation results showed a good linear relationship for the 11 sweeteners within the corresponding concentration ranges, with average recoveries of 77.29%~98.82% and relative standard deviations (RSDs) in the range of 1.5%~9.6% (n=6), limit of detection of aloin being 150.0 μg/L, and limits of detection of other 10 sweeteners in the range of 1.0~15.0 μg/L. The testing of real samples revealed that sodium cyclamate was detected in two fruit beverages (at concentrations of 0.8 mg/L and 190.9 mg/L, respectively), and stevioside and rebaudioside A were detected in one tea beverage (at concentrations of 94.2 μg/L and 62.1 μg/L, respectively), with no other unknown steviol glycoside sweeteners being detected. The results showed that although the contents of the sweeteners in the tested beverages did not exceed the maximum allowable limit specified in the standards, there were instances of incomplete labeling contents, suggesting a need for stronger supervision and management of food labeling.