Adenosine 5′-monophosphate in powdered milk was quantitated by liquid chromatography-isotope dilution mass spectrometry.The uncertainty was calculated.This could provide information for the further quantitative measu...Adenosine 5′-monophosphate in powdered milk was quantitated by liquid chromatography-isotope dilution mass spectrometry.The uncertainty was calculated.This could provide information for the further quantitative measurement and utilization of 5′-nucleotide acid as food additive.展开更多
A method for the determination of vitamin A in milk powder was developed by high performance liquid chromatography-isotope dilution mass spectrometry(HPLC-ID MS) and using deuterium-labeled vitamin A as an internal st...A method for the determination of vitamin A in milk powder was developed by high performance liquid chromatography-isotope dilution mass spectrometry(HPLC-ID MS) and using deuterium-labeled vitamin A as an internal standard.RSD of the method was 2.85%.This method was applied in the determination of standard reference material SRM 1849 with satisfactory results.展开更多
The mass of oligonucleotides was quantitated by liquid chromatography-isotope dilution mass spectrometry.The uncertainty was calculated.This could provide information for the further quantitative measurement and utili...The mass of oligonucleotides was quantitated by liquid chromatography-isotope dilution mass spectrometry.The uncertainty was calculated.This could provide information for the further quantitative measurement and utilization of DNA.展开更多
文摘提出了同位素稀释-液相色谱-串联质谱法测定鱼、虾、蟹、贝4类水产品中甲霜灵残留量的方法。取样品(5±0.05)g,加入10 ng的内标甲霜灵-d 6,静置10 min,用10 mL含1%(体积分数)乙酸的乙腈溶液涡旋混合、离心。取上清液,于45℃氮吹至0.5 mL以下,加入7.5 mL 20%(体积分数,下同)乙腈溶液混匀,用7.5 mL正己烷去脂,Agela Cleanert S C_(18)固相萃取柱富集净化。所得溶液于45℃氮吹至干,用1 mL 20%乙腈溶液复溶,混匀后过0.22μm针式水相尼龙滤膜,滤液收集至进样小瓶中。以SHISEIDO CAPCELL PAK C_(18)色谱柱为固定相,以不同体积比的0.1%(体积分数)甲酸溶液和乙腈的混合液为流动相进行梯度洗脱,内标法定量。结果表明,甲霜灵标准曲线的线性范围为1.0~100.0μg·L^(-1),检出限(3S/N)为0.5μg·kg^(-1)。以不同品种水产品为空白基质,在1.0,2.0,10.0μg·kg^(-1)等3个浓度水平下,甲霜灵的回收率为93.8%~105%,测定值的相对标准偏差(n=6)均小于13%。
文摘Adenosine 5′-monophosphate in powdered milk was quantitated by liquid chromatography-isotope dilution mass spectrometry.The uncertainty was calculated.This could provide information for the further quantitative measurement and utilization of 5′-nucleotide acid as food additive.
文摘A method for the determination of vitamin A in milk powder was developed by high performance liquid chromatography-isotope dilution mass spectrometry(HPLC-ID MS) and using deuterium-labeled vitamin A as an internal standard.RSD of the method was 2.85%.This method was applied in the determination of standard reference material SRM 1849 with satisfactory results.
文摘The mass of oligonucleotides was quantitated by liquid chromatography-isotope dilution mass spectrometry.The uncertainty was calculated.This could provide information for the further quantitative measurement and utilization of DNA.
