质谱学报2025，Vol.46Issue(2)：217-223,7.DOI:10.7538/zpxb.2024.0112
食品接触塑料中6种金属离子迁移量测定方法研究
Determination of Migration of Six Metal Ions in Food Contact Plastic
摘要
Abstract
Additives containing metal ions can be added to food contact plastic as stabilizer,catalyzer,colorant,etc.Food safety standards also request specific migration limits(SMLs)for metal elements.The most common methods for determination of multiple metal elements in solutions are inductively coupled plasma-optical emission spectrometry(ICP-OES)and inductively coupled plasma-mass spectrometry(ICP-MS).Metal ions in solution can cluster or coordinate with organic compounds to form new stable complicated ions,which can be detected by electrospray ionization-mass spectrometry(ESI-MS).To apply this nature for determination of metal ions by liquid chromatography-quadrupole time-of-flight mass spectrometry(LC-QTOF MS),further parameter optimization is needed.In this study,five kinds of aqueous mobile phases,including 0.02%(W/W)glycollic acid,0.02%(V/V)formic acid,0.10%(V/V)formic acid,5 mmol/L ammonium formate,and 5 mmol/L ammonium formate-0.02%(V/V)formic acid,were compared for better performance of MS analysis coupled to Ultimate Hilic amide column.Different acids can give rise to form different cluster ions.Higher concentration of formic acid in aqueous mobile phase can produce better peak shape but doesn't enhance signal to noise ratio apparently.Addition of ammonium ions can weak the signal of cluster ions.With 0.02%formic acid as the mobile phase,Cd2+,Co2+,Mn2+,Ni2+,Zn2+form[M(HCOO)+CH3CN]+parent ion,while Cu2+forms[M+2CH3CN]+parent ion.The parent ions of Cd2+,Co2+,Mn2+and Zn2+are collided to form[M]+,[M(H)]+,[M(H)+CH3CN]+,[M(HCOO)]+,while the parent ion of Ni2+to form[Ni]+,[Ni(H)]+,[Ni+CH3CN]+,[Ni(H)+CH3CN]+,[Ni+CH3CN+N2]+,[NiO+CH3CN]+,[Ni(OH)+CH3CN]+,the parent ion of Cu2+to form[Cu]+,[Cu+CH3CN]+,[Ni+CH3CN+N2]+.Finally,the optimized LC-QTOF MS method was applied to determine the migration of Cd2+,Co2+,Cu2+,Mn2+,Ni2+,Zn2+in food contact plastic.ESI-QTOF MS analysis was performed under positive ion mode(ESI+)and multiple reaction monitor high resolution(MRM HR)mode.The limits of detection(LODs)of 6 metal ions range from 0.02 to 0.08 mg/kg,recoveries are 88.6%-115%,and the relative standard deviations are between 0.3%and 6.1%.Migration solutions from 24 batches of food contact plastic were tested,while 4 of them contain detectable Cu2+,Mn2+and Zn2+.The proposed method is easily appliable to determine metal ions in high proportion ethanol aqueous solution without needing to remove the ethanol.It is suitable for compliance screening of cobalt,copper,manganese,zinc in migration solution from food contact plastic,and provides a valuable reference for the analysis of unknown hazardous substances from food contact plastic.关键词
液相色谱-四极杆-飞行时间质谱(LC-QTOF MS)/金属离子/食品接触塑料/迁移量Key words
liquid chromatography-quadrupole time-of-flight mass spectrometry(LC-QTOF MS)/metal ion/food contact plastic/migration分类
化学化工引用本文复制引用
凌光耀,熊小婷,刘春生,陈意光,江奋万,仇旭前,李慧勇,黄晓钢,何国山..食品接触塑料中6种金属离子迁移量测定方法研究[J].质谱学报,2025,46(2):217-223,7.基金项目
广州市科技计划项目(2023B04J0436,2023B04J0407) （2023B04J0436,2023B04J0407）
广州市院士专家工作站(2024-D012) （2024-D012）
广东省市场监督局科技项目(2024CZ21,2022CZ05) （2024CZ21,2022CZ05）
