Via multi-dimensional gas chromatography, configured with parallel dual-channel, double detectors, valves switching and back flushing, rapid analysis of the gas compositions consisting of C1-C5 hydrocarbons and perman...Via multi-dimensional gas chromatography, configured with parallel dual-channel, double detectors, valves switching and back flushing, rapid analysis of the gas compositions consisting of C1-C5 hydrocarbons and permanent gases, such as CO2, H2S, H2, and CO, for direct coal liquefaction has been realized. With four packed chromatographic columns, which are Hayesep-Q pre-column, Hayesep-Q column, molecular sieve 5A column and one PLOT A1203 S capillary column, the gas compositions for direct coal liquefaction are analyzed qualitatively and quantitatively by the external standard method. The determination method has such advantages as excellent separation, simple operation, rapid analysis and accurate results.展开更多
使用超高效液相色谱⁃串联质谱仪,采用同位素内标法定量,建立枸杞中苦参碱和氧化苦参碱的测定方法。样品经1.0%磷酸水溶液超声提取,强阳离子固相萃取柱净化,10 mL 5%氨水甲醇溶液洗脱,采用0.1%甲酸水溶液和甲醇为流动相,梯度洗脱,通过T3...使用超高效液相色谱⁃串联质谱仪,采用同位素内标法定量,建立枸杞中苦参碱和氧化苦参碱的测定方法。样品经1.0%磷酸水溶液超声提取,强阳离子固相萃取柱净化,10 mL 5%氨水甲醇溶液洗脱,采用0.1%甲酸水溶液和甲醇为流动相,梯度洗脱,通过T3色谱柱分离,电喷雾离子源正离子扫描模式、多反应监测模式检测。通过考察不同种类提取溶剂、超声时间、固相萃取条件下目标化合物峰面积,确定最优前处理方式。结果表明:苦参碱和氧化苦参碱在0.5~50.0μg/kg范围内呈现良好线性关系,相关系数(R2)均大于0.999。方法检出限0.05μg/kg,定量限0.2μg/kg。低、中、高3个浓度加标回收试验,苦参碱回收率范围在76.3%~90.7%,相对标准偏差(relative standard deviation,RSD)在2.2%~7.4%,氧化苦参碱回收率范围在79.2%~89.0%,RSD在3.1%~6.6%。该方法适用于枸杞中苦参碱和氧化苦参碱检测。展开更多
文摘Via multi-dimensional gas chromatography, configured with parallel dual-channel, double detectors, valves switching and back flushing, rapid analysis of the gas compositions consisting of C1-C5 hydrocarbons and permanent gases, such as CO2, H2S, H2, and CO, for direct coal liquefaction has been realized. With four packed chromatographic columns, which are Hayesep-Q pre-column, Hayesep-Q column, molecular sieve 5A column and one PLOT A1203 S capillary column, the gas compositions for direct coal liquefaction are analyzed qualitatively and quantitatively by the external standard method. The determination method has such advantages as excellent separation, simple operation, rapid analysis and accurate results.
文摘取1 g样品,加入10μg·L^(-1)混合同位素内标溶液、10 m L乙腈、1 m L水和0.5 g氯化钠,匀浆2 min,超声30 min,离心10 min,在上清液中加入2 m L正己烷,振荡5 min,静置分层,在下层相中依次加入200 mg N-丙基乙二胺(PSA)、200 mg C18和1 500 mg无水硫酸镁,振荡5 min,离心10 min。取1 m L上清液,于25℃氮吹至近干,加入1 m L乙酸乙酯复溶,过0.22μm聚四氟乙烯(PTFE)针式过滤头,滤液供气相色谱-串联质谱法分析。在HP-INNOWAX色谱柱上以程序升温条件分离各N-亚硝胺类化合物,以电子轰击离子源电离,多反应监测(MRM)模式检测,同位素内标法定量。结果显示:12种N-亚硝胺类化合物的质量浓度均在一定范围内和对应的响应值与内标响应值的比值呈线性关系,检出限(3S/N)为0.17~0.66μg·kg^(-1)。对5种类型化妆品空白基质进行5,20,100μg·kg^(-1)加标水平的回收试验,回收率为81.6%~117%,测定值的相对标准偏差(n=6)为1.2%~4.8%。方法用于市售5种类型化妆品样品的分析,均未检出12种N-亚硝胺类化合物。
文摘使用超高效液相色谱⁃串联质谱仪,采用同位素内标法定量,建立枸杞中苦参碱和氧化苦参碱的测定方法。样品经1.0%磷酸水溶液超声提取,强阳离子固相萃取柱净化,10 mL 5%氨水甲醇溶液洗脱,采用0.1%甲酸水溶液和甲醇为流动相,梯度洗脱,通过T3色谱柱分离,电喷雾离子源正离子扫描模式、多反应监测模式检测。通过考察不同种类提取溶剂、超声时间、固相萃取条件下目标化合物峰面积,确定最优前处理方式。结果表明:苦参碱和氧化苦参碱在0.5~50.0μg/kg范围内呈现良好线性关系,相关系数(R2)均大于0.999。方法检出限0.05μg/kg,定量限0.2μg/kg。低、中、高3个浓度加标回收试验,苦参碱回收率范围在76.3%~90.7%,相对标准偏差(relative standard deviation,RSD)在2.2%~7.4%,氧化苦参碱回收率范围在79.2%~89.0%,RSD在3.1%~6.6%。该方法适用于枸杞中苦参碱和氧化苦参碱检测。
