宁夏枸杞尼古丁来源研究

Sources of Nicotine in Lycium barbarum

目的:研究枸杞子中尼古丁来源,为设定科学合理的枸杞子尼古丁限量标准提供参考。方法:采集34份无外源污染宁夏枸杞的根、茎、叶、花、果样品,采用超高效液相色谱-串联质谱法(UPLC-MS/MS)研究宁夏枸杞不同部位样品尼古丁含量;收集124份人工种植宁夏枸杞成熟果实(枸杞子)样品及62份宁夏枸杞生产常用投入品,采用高效液相色谱-串联质谱法(HPLC-MS/MS)检测宁夏枸杞成熟果实及宁夏枸杞生产常用投入品中尼古丁含量。结果:无外源污染情况下,宁夏枸杞的根、茎、叶、花、果中均检出微量尼古丁,尼古丁质量分数≤0.00361 mg·kg^(-1);21份宁夏枸杞成熟果实中检出尼古丁,尼古丁质量分数为0.00055~0.03030 mg·kg^(-1)。其中,仅7份样品尼古丁含量超过欧盟最大残留限量标准(0.01 mg·kg^(-1)),超标样品中有6份宁夏枸杞成熟果实在生产中使用过尼古丁严重超标的苦参碱投入品。结论:宁夏枸杞可内源合成微量尼古丁,市场检测出尼古丁超标的枸杞子可能与生产过程中使用含有尼古丁投入品有关。

Objective:To study the sources of nicotine in Lycii Fructus,so as to provide reference for the setting of scientific and reasonable maximum residue limit(MRL)of nicotine in goji.Methods:34 root,stem,leaf,flower,and fruit samples of Lycium barbarum without exogenous pollution were collected for detecting the nicotine content in each part by ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).Then 124 mature fruit(goji)samples and 62 commonly used production inputs of L.barbarum were collected for determining the nicotine content in mature fruits and production inputs by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).Results:In the absence of exogenous pollution,trace amounts of nicotine were detected in the roots,stems,leaves,flowers,and fruits of L.barbarum,with the nicotine mass fraction not exceeding 0.00361 mg·kg^(-1).The nicotine was detected in 21 mature fruit samples,with the detected amount ranging from 0.00055 to 0.03030 mg·kg^(-1).The nicotine content in 7 of these samples exceeded the European Union(EU)maximum tesidue limits(MRLs)value(0.01 mg·kg^(-1)),and the excessive nicotine in 6 mature fruit samples was attributed to the use of matrine inputs containing a very high level of nicotine in their production.Conclusion:L.barbarum endogenously synthesizes a trace amount of nicotine.Goji with excessive nicotine detected in the market may be related to the use of nicotine-containing inputs in the production process.