气相色谱-三重四极杆质谱法测定粮谷中咪鲜胺及其代谢物残留量

目的 建立粮谷中咪鲜胺及其代谢产物2,4,6-三氯苯酚残留测定的气相色谱-三重四极杆质谱(gas chromatography-triple quadrupole mass spectrometry,GC-MS/MS)的分析方法.方法 试样加水涡旋混匀经1％乙酸乙腈提取,通过N-丙基乙二胺(primary second...     

液相色谱-三重四级杆质谱法测定苹果中 腈苯唑农药残留

目的 为加强我国苹果中腈苯唑农药残留的监控,保护我国苹果在国际贸易中的合理地位,建立了苹果中腈苯唑的液相色谱-三重四极杆质谱(UPLC-MS/MS)测定方法。方法 样品经乙腈提取,超高效液相色谱-串联质谱下进行测定。结果 目标物在0.005~0.50 mg/L范围内成线性,相关系数r>0.99,空白样品中分析物在添加浓度为0.01、0.02、0.05 mg/kg时,平均回收率为89.6%~93.0%,相对标准偏差为2.4%~7.9%,定量限为0.01 mg/kg。结论 本方法操作简便、灵敏度高、准确度好,能满足农残检测分析的要求。     

Direct characterisation of phenolic antioxidants in infusions from four Mapuche medicinal plants by liquid chromatography with diode array detection (HPLC-DAD) and electrospray ionisation tandem mass spectrometry (HPLC-ESI-MS)

A simple, fast and direct method was developed for the qualitative analysis of phenolic constituents from infusions of Mapuche medicinal plants. Teas made of Linum chamissonis Schiede, Quinchamalium chilensis Mol., Adesmia emarginata Clos. and Escallonia illinita K. Presl. were analysed by high-performance liquid chromatography with diode array detector (HPLC-DAD) and electrospray mass spectrometry (ESI-MS). This technique allowed for the first time the tentative identification of 16 phenolic compounds in E. illinita, 27 in Q. chilensis, 10 in L. chamissonis and 19 in A. emarginata. The compounds were mainly phenolic acids, flavonoid glycosides, anthocyanins and tannins. The total phenolic and flavonoid content of the infusions was assessed as well as the free radical scavenging capacity measured by the bleaching of a solution of the 2,2-diphenyl-1-picrylhydrazyl (DPPH⁻) radical. From the four species, Q. chilensis exhibited the strongest antioxidant activity with highest total phenolic and flavonoid content.     

Study of chloropropanols in soy sauce by gas chromatography-triple quadrupole mass spectrometry with coupled column separation without derivatisation

A qualitative and quantitative determination method for chloropropanols in soy sauce was developed by GC-MS/MS with coupled column separation without derivatisation. The target compounds were 1,3-dichloropropan-2-ol (1,3-DCP), 2,3-dichloropropan-1-ol (2,3-DCP), 3-monochloropropane-1,2-diol (3-MCPD) and 2-monochloropropane-1,3-diol (2-MCPD). 3-MCPD-d₅ was used as an isotope internal standard for MCPDs and 1,3-DCP-d₅ for DCPs. After spiking with internal standards and mixed with 1?g of Extrelut? NT, about 1?g of the sample was washed by 4?ml of hexane and the analytes were eluted with 15?ml of 95% (v/v) ethyl ether/hexane mixture. The concentrated extract was directly injected without derivatisation, separated by a coupled column – a 3?m Innowax (polyethylene glycol) combined with a 30?m DB-5?ms ((5%-phenyl)-methylpolysiloxane) by a quartz capillary column connector – and detected by GC-MS/MS. The limits of detection (LODs) in the sample matrix were 1.0, 2.5, 5.0 and 5.0?µg?kg^?1 for the above chloropropanols, respectively. The relative proportions of 2-MCPD/3-MCPD ranged from 0.19 to 3.74 in soy sauce samples. 2,3-DCP and 2-MCPD were more stable than 1,3-DCP and 3-MCPD under alkaline condition. The levels of chloropropanols can be decreased by an alkaline treatment process.     

正己烷提取-高效液相色谱法及其串联质谱法分别测定婴幼儿配方奶粉中维生素A、D3含量

目的 建立了正己烷提取、液相色谱和液相色谱串联质谱分别测定婴幼儿配方奶粉中维生素A(VA)和维生素D₃(VD₃)含量的方法。方法 样品中加入VD₃-d₃内标后皂化,正己烷提取,去离子水清洗正己烷提取液以去除提取液中的氢氧化钾,加入氯化钠促进水和正己烷两相分层,将洗至中性的正己烷提取液浓缩至干,甲醇定容至10 mL,取1 mL溶液用液相色谱法测定VA,剩余的9 mL定溶液浓缩至干后再用1 mL甲醇复容,液相色谱串联质谱测定VD₃。结果 VA的线性范围为0.2～6.0 μg/mL,方法检出限为30 μg/100g,方法定量限为100 μg/100g;VD₃的线性范围为0.01～0.20 μg/mL,方法检出限为0.5 μg/100g,方法定量限为1.0 μg/100g。通过质控样品验证方法准确度和精密度,测定值均在质控区间内,且批内相对标准偏差和批间相对标准偏差均小于5%。使用该方法成功通过了2020年婴幼儿配方奶粉中VA、VD₃样品能力验证考核。结论 该方法所用提取试剂少,且操作简单快捷,适用于婴幼儿配方奶粉中VA和VD₃的测定。