气相色谱-串联质谱法保留时间锁定快速定量茶叶中丙烯酰胺

Rapid determination of acrylamide in tea by gas chromatography - triple quadrupole mass spectrometry combined with retention time locking

目的 以13C3-丙烯酰胺为同位素内标,基于气相色谱-串联质谱法(GC-MS/MS),构建茶叶中丙烯酰胺快速准确定量分析方法,并根据该定量分析方法对丽水主要产茶区的不同茶叶样品进行丙烯酰胺测定,为后期数据分析提供可靠依据。方法 以本地区绿茶、红茶为方法检测材料,参照GB 5009.204—2014 《食品安全国家标准食品中丙烯酰胺的测定》,经实验优化后,采用内标法GC-MS/MS保留时间锁定(DMRM)法检测茶叶中丙烯酰胺含量。结果 茶样品中丙烯酰胺只有少数检出,其中红茶样品检出值相对偏高。丙烯酰胺在浓度为0.02 mg/L~10 mg/L内具有良好的线性关系,相关线性系数在0.999以上;检出限为0.03 mg/kg,定量限为0.09 mg/kg,其中同一阴性茶叶样品加标为0.1 mg/kg、0.5 mg/kg、1.0 mg/kg,回收率均在94%以上,相对标准偏差均在5%以下(n=6)。结论 茶叶中丙烯酰胺产生的主要原因为茶叶加工过程中过热处理所致,合理控制制茶工艺中的温度,可有效降低丙烯酰胺的产生。本检测方法无需衍生就可快速测定茶叶中的丙烯酰胺含量,检测成本低、分析时间短、方法前处理简便,优于国家检测标准。

Objective With 13 C3-acrylamide as the isotope internal standard,based on gas chromatography-triple quadru⁃pole mass spectrometry(GC-MS/MS)method,a rapid and quantitative analysis method for acrylamide in tea was established.According to this quantitative analysis method,acrylamide was determined in different tea samples from the main tea producing areas in Lishui,providing reliable basis for data analysis.Methods With green tea and black tea in Lishui area as the detec⁃tion samples,and referring to GB 5009.204—2014 National Food Safety Standard Determination of Acrylamide in Food,the internal standard-GC-MS/MS-retention time locking(DMRM)method was used to detect the acrylamide content in tea after experimental optimization.Results Acrylamide was only detected in a few tea samples,and the detection rate in black tea samples was relatively high.Acrylamide had a good linear relationship in the concentration range of 0.02 mg/L-10 mg/L,and the correlation linear coefficient(r)was above 0.999.The detection limit was 0.03 mg/kg,and the quantification limit was 0.09 mg/kg.When the spiking of the same negative tea sample was respectively 0.1 mg/kg,0.5 mg/kg,and 1.0 mg/kg,the recoveries were all above 94%,and the relative standard deviations(RSDs)were all below 5%(n=6).Conclusion Acryl⁃amide in tea is mainly caused by overheating during tea processing.Reasonable control of temperature in tea making process can effectively reduce the generation of acrylamide.This method can quickly determine the content of acrylamide in tea without derivatization,with low detection cost,short analysis time,and simple pretreatment,which is superior to the national detection standard.