A self-ordered ring(SOR) fluorescence microscopic imaging technique has been developed for the determination of trace amounts of sulfadiazine based on its derivatization with fluorescamine.In the presence of HAc-NaAc ...A self-ordered ring(SOR) fluorescence microscopic imaging technique has been developed for the determination of trace amounts of sulfadiazine based on its derivatization with fluorescamine.In the presence of HAc-NaAc buffer solution(pH 3.12) and polyvinyl alcohol-124(PVA-124),the droplet containing fluorescamine derivatized sulfadiazine can form a SOR on the solid support after solvent evaporation with the diameter of 1.86mm and its ring belt width of 54.9 μ m.The quantitative analysis of sulfadiazine is achieved with the linear range of 7.8×10-14 ～1.8×10-12 mol·ring-1(3.9×10-7 ～9.0×10-6 mol·L-1) and detection limit of 7.8×10-15 mol·ring-1(3.9×10-8 mol·L-1) when 0.2 μ L droplet was spotted.The technique has been satisfactorily applied to the determination of sulfadiazine in the tablet,synthetic sample and residues in six different milk samples with the recoveries of 91.0%～105.8%,respectively,and RSDs less than 4.4%.展开更多
Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, s...Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview of the derivatization methods in the LC/MS analysis of neurosteroids or neuroactive neurosteroids, which are synthesized and accumulated in the nervous system The derivatization of pregnenolone 3 sulfate, one of these steroids, with 4 ( N,N dimethylaminosulfonyl) 7 hydrazino 2,1,3 benzoxadiazole gave a satisfactory sensitivity during the quantitative analysis using LC/ESI MS The obtained results are much lower than those previously obtained using gas chromatography/mass spectrometry or radioimmunoassay On the other hand, the derivatization to acetate was useful for the treatment of labile catechol estrogens in rat brains and gave enough structural information in LC/APCI MS, which confirmed the existence of catechol estrogens in mammalian展开更多
建立以邻苯二甲醛为衍生试剂,柱前衍生-HPLC测定特殊医学用途奶粉中牛磺酸含量的方法。选用C18色谱柱进行产物分离,并对衍生试剂用量、流动相比例、流速、混合次数、衍生后等待时间等因素进行优化。结果表明衍生试剂用量30μL,流动相体...建立以邻苯二甲醛为衍生试剂,柱前衍生-HPLC测定特殊医学用途奶粉中牛磺酸含量的方法。选用C18色谱柱进行产物分离,并对衍生试剂用量、流动相比例、流速、混合次数、衍生后等待时间等因素进行优化。结果表明衍生试剂用量30μL,流动相体积比20∶80,流速0.6 mL/min,混合6次,衍生完成后等待时间0 min时,衍生物的峰面积和峰形最优。在此实验条件下3种不同浓度牛磺酸标准品的精密度测定衍生物峰面积相对标准偏差(relative standard deviation,RSD)为0.08%~0.75%,精密度高。对两种特殊医学用途奶粉中牛磺酸含量进行检测,重复性实验测定RSD分别为0.67%和0.37%,重复性稳定;样品加标平均回收率分别为97.6%~104.5%和106.0%~110.3%,回收率好。该研究方法反应条件温和、操作性强,适用于特殊医学用途奶粉中牛磺酸含量的测定。展开更多
建立了食用油中青霉酸残留量的柱前衍生-气相色谱-三重四级杆串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)检测方法。样品采用乙腈提取、正己烷除脂,N-甲基-N-(三甲基硅烷)三氟乙酰胺(MSTFA)硅烷化衍生后供GC-MS/M...建立了食用油中青霉酸残留量的柱前衍生-气相色谱-三重四级杆串联质谱(gas chromatography-tandem mass spectrometry,GC-MS/MS)检测方法。样品采用乙腈提取、正己烷除脂,N-甲基-N-(三甲基硅烷)三氟乙酰胺(MSTFA)硅烷化衍生后供GC-MS/MS测定,外标法定量。结果表明,该方法在2~50 ng/mL范围内具有良好的线性,相关系数R 2为0.9991,定量限(LOQ)为2.0μg/kg,玉米油、花生油、菜籽油中三水平加标回收率为85.2%~93.9%,相对标准偏差为4.7%~7.5%。该方法快速高效,灵敏度高,专一性强,可满足食用油中青霉酸残留量检测要求。展开更多
基金The National Nature Science Foundation of China(Grant Nos.20767004,21177163)111 Project B08044+1 种基金"985 Project"of Minzu University of China(MUC 98507-08)"211 Project"of Minzu University of China(MUC 02121103)
文摘A self-ordered ring(SOR) fluorescence microscopic imaging technique has been developed for the determination of trace amounts of sulfadiazine based on its derivatization with fluorescamine.In the presence of HAc-NaAc buffer solution(pH 3.12) and polyvinyl alcohol-124(PVA-124),the droplet containing fluorescamine derivatized sulfadiazine can form a SOR on the solid support after solvent evaporation with the diameter of 1.86mm and its ring belt width of 54.9 μ m.The quantitative analysis of sulfadiazine is achieved with the linear range of 7.8×10-14 ～1.8×10-12 mol·ring-1(3.9×10-7 ～9.0×10-6 mol·L-1) and detection limit of 7.8×10-15 mol·ring-1(3.9×10-8 mol·L-1) when 0.2 μ L droplet was spotted.The technique has been satisfactorily applied to the determination of sulfadiazine in the tablet,synthetic sample and residues in six different milk samples with the recoveries of 91.0%～105.8%,respectively,and RSDs less than 4.4%.
文摘Liquid chromatography/mass spectrometry (LC/MS) is now considered to be the most promising analytical method for the determination of biological substances, especially nonvolatile or highly polar substances However, some compounds do not show enough sensitivity in LC/MS and soft ionization methods commonly used in LC/MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), sometimes do not give satisfactory structural information This report presents an overview of the derivatization methods in the LC/MS analysis of neurosteroids or neuroactive neurosteroids, which are synthesized and accumulated in the nervous system The derivatization of pregnenolone 3 sulfate, one of these steroids, with 4 ( N,N dimethylaminosulfonyl) 7 hydrazino 2,1,3 benzoxadiazole gave a satisfactory sensitivity during the quantitative analysis using LC/ESI MS The obtained results are much lower than those previously obtained using gas chromatography/mass spectrometry or radioimmunoassay On the other hand, the derivatization to acetate was useful for the treatment of labile catechol estrogens in rat brains and gave enough structural information in LC/APCI MS, which confirmed the existence of catechol estrogens in mammalian
文摘建立以邻苯二甲醛为衍生试剂,柱前衍生-HPLC测定特殊医学用途奶粉中牛磺酸含量的方法。选用C18色谱柱进行产物分离,并对衍生试剂用量、流动相比例、流速、混合次数、衍生后等待时间等因素进行优化。结果表明衍生试剂用量30μL,流动相体积比20∶80,流速0.6 mL/min,混合6次,衍生完成后等待时间0 min时,衍生物的峰面积和峰形最优。在此实验条件下3种不同浓度牛磺酸标准品的精密度测定衍生物峰面积相对标准偏差(relative standard deviation,RSD)为0.08%~0.75%,精密度高。对两种特殊医学用途奶粉中牛磺酸含量进行检测,重复性实验测定RSD分别为0.67%和0.37%,重复性稳定;样品加标平均回收率分别为97.6%~104.5%和106.0%~110.3%,回收率好。该研究方法反应条件温和、操作性强,适用于特殊医学用途奶粉中牛磺酸含量的测定。
