Modern porous monoliths have been conceived as a new class of stationary phases for high performance liquid chromatography(HPLC) in classical columns in the early 1990s and later extended to the capillary format.These...Modern porous monoliths have been conceived as a new class of stationary phases for high performance liquid chromatography(HPLC) in classical columns in the early 1990s and later extended to the capillary format.These monolithic materials are prepared using simple processes carried out in an external mold(inorganic monoliths) or within the confines of the column(organic monoliths and all capillary columns).These methods afford macroporous materials with large through-pores that enable applications in a rapid flow-through mode.Since all the mobile phase must flow through the monolith,the convection considerably accelerates mass transport within the monolithic separation medium and improves the separations.As a result,the monolithic columns perform well even at very high flow rates.The applications of monolithic capillary columns are demonstrated on numerous separations in the HPLC mode.展开更多
为简化前处理过程,降低方法的检出限,进行了题示研究。采集鱼塘底泥样品,混匀、缩分、冷冻干燥、除杂、研磨、过筛后混匀,分取5.00 g,加入10.0μg·L^(-1)^(13)C_(6)-氯硝柳胺水合物标准溶液0.2 m L和含2.0%(体积分数)氨水的乙腈溶...为简化前处理过程,降低方法的检出限,进行了题示研究。采集鱼塘底泥样品,混匀、缩分、冷冻干燥、除杂、研磨、过筛后混匀,分取5.00 g,加入10.0μg·L^(-1)^(13)C_(6)-氯硝柳胺水合物标准溶液0.2 m L和含2.0%(体积分数)氨水的乙腈溶液20 m L,涡旋1 min,超声10 min,离心8 min。上清液于45℃旋蒸至近干,加入2.00 m L 70%(体积分数)乙腈溶液涡旋溶解残留物,再加入200 mg C18涡旋振荡30 s,离心5 min。收集上清液,过0.22μm有机滤膜,滤液采用高效液相色谱-串联质谱法测定。在色谱分析中,以Waters Atiantis^(TM) d C_(18)色谱柱为固定相,水-乙腈体系为流动相进行梯度洗脱;在质谱分析中,以电喷雾离子源负离子(ESI-)模式电离,选择反应监测(SRM)模式检测,内标法定量。结果显示,氯硝柳胺的质量浓度在0.20~50.00μg·L^(-1)内和其定量离子峰面积与同位素内标定量离子峰面积的比值呈线性关系,检出限(3S/N)为0.2μg·kg^(-1)。按照标准加入法进行回收试验,回收率为92.1%~113%,测定值的相对标准偏差(n=6)为1.6%~5.9%。方法用于实际样品的分析,检出的氯硝柳胺的质量分数为0.580~2.18 mg·kg^(-1)。展开更多
提出了在线固相萃取-高效液相色谱-串联质谱法(HPLC-MS/MS)同时测定家禽养殖废水中6种抗菌类药物(氟苯尼考、磺胺甲基嘧啶、痢菌净、氟哌酸、阿米卡星和头孢唑林钠)残留量的方法。取家禽养殖废水样品用纱布过滤,再用滤纸过滤,取滤液10.0...提出了在线固相萃取-高效液相色谱-串联质谱法(HPLC-MS/MS)同时测定家禽养殖废水中6种抗菌类药物(氟苯尼考、磺胺甲基嘧啶、痢菌净、氟哌酸、阿米卡星和头孢唑林钠)残留量的方法。取家禽养殖废水样品用纱布过滤,再用滤纸过滤,取滤液10.0 m L,通过Waters Oasis HLB固相萃取柱在线固相萃取,以Capcell PAK AG ODS C18色谱柱为固定相,以不同体积比的0.1%(体积分数)甲酸溶液-乙腈混合液为流动相进行梯度洗脱,采用电喷雾离子(ESI)源,在正离子(ESI+)扫描模式下进行多反应监测(MRM)模式质谱分析。结果表明,6种抗菌类药物的质量浓度在0.005~5.0 mg·L^(-1)内与对应的峰面积呈线性关系,检出限(3S/N)为0.018 3~0.072 2μg·L^(-1)。按照标准加入法进行回收试验,回收率为83.8%~105%,测定值的相对标准偏差(n=6)均小于5.0%。方法用于测定5个实际家禽养殖废水中6种抗菌类药物的残留量,检出量为16.09~277.14μg·L^(-1)。展开更多
钩吻生物碱是引起钩吻中毒的主要成分,严重威胁人民群众的生命健康。该文建立了分散固相萃取-高效液相色谱串联质谱(high performance liquid chromatography tandem mass spectrometry,HPLC-MS/MS)法同时快速分析食品中10种钩吻生物碱...钩吻生物碱是引起钩吻中毒的主要成分,严重威胁人民群众的生命健康。该文建立了分散固相萃取-高效液相色谱串联质谱(high performance liquid chromatography tandem mass spectrometry,HPLC-MS/MS)法同时快速分析食品中10种钩吻生物碱的方法。食品样品经1%(体积分数)HCl超声提取后调pH值至11~12,加入乙腈涡旋振荡提取后,以NaCl辅助分层离心,上清液经无水Na_(2)SO_(4)和C18脱水净化后,离心所得上清液吹干复溶,在电喷雾正离子模式(ESI^(+))下,采用多反应监测模式,以0.1%氨水-10 mmol/L乙酸铵溶液和乙腈为流动相,经Hilic(2.1 mm×100 mm×1.7μm)柱梯度洗脱分离测定,采用基质标曲外标法定量。结果表明,钩吻生物碱的基质效应为13.1%~3692.7%,在0.5~10.0 ng/mL线性良好,相关系数(R)在0.995以上,检出限和定量限分别为0.075~0.225 ng/g和0.250~0.750 ng/g,在4种食品基质中3个水平的加标回收率为79.3%~118.7%,相对标准偏差为0.1%~12.1%(n=6)。该方法操作简单、高效、灵敏度高,对误食钩吻引起的急性中毒事件诊断并采取必要措施保障生命安全具有重要现实意义。展开更多
基金Supported by grants of the National Institute of General Medical Sciences,National Institutes of Health(GM-48364),and the Materials Sciences and Engineering Division of the U.S.Department of Energy(DE-AC02-05CH11231).
文摘Modern porous monoliths have been conceived as a new class of stationary phases for high performance liquid chromatography(HPLC) in classical columns in the early 1990s and later extended to the capillary format.These monolithic materials are prepared using simple processes carried out in an external mold(inorganic monoliths) or within the confines of the column(organic monoliths and all capillary columns).These methods afford macroporous materials with large through-pores that enable applications in a rapid flow-through mode.Since all the mobile phase must flow through the monolith,the convection considerably accelerates mass transport within the monolithic separation medium and improves the separations.As a result,the monolithic columns perform well even at very high flow rates.The applications of monolithic capillary columns are demonstrated on numerous separations in the HPLC mode.
文摘为简化前处理过程,降低方法的检出限,进行了题示研究。采集鱼塘底泥样品,混匀、缩分、冷冻干燥、除杂、研磨、过筛后混匀,分取5.00 g,加入10.0μg·L^(-1)^(13)C_(6)-氯硝柳胺水合物标准溶液0.2 m L和含2.0%(体积分数)氨水的乙腈溶液20 m L,涡旋1 min,超声10 min,离心8 min。上清液于45℃旋蒸至近干,加入2.00 m L 70%(体积分数)乙腈溶液涡旋溶解残留物,再加入200 mg C18涡旋振荡30 s,离心5 min。收集上清液,过0.22μm有机滤膜,滤液采用高效液相色谱-串联质谱法测定。在色谱分析中,以Waters Atiantis^(TM) d C_(18)色谱柱为固定相,水-乙腈体系为流动相进行梯度洗脱;在质谱分析中,以电喷雾离子源负离子(ESI-)模式电离,选择反应监测(SRM)模式检测,内标法定量。结果显示,氯硝柳胺的质量浓度在0.20~50.00μg·L^(-1)内和其定量离子峰面积与同位素内标定量离子峰面积的比值呈线性关系,检出限(3S/N)为0.2μg·kg^(-1)。按照标准加入法进行回收试验,回收率为92.1%~113%,测定值的相对标准偏差(n=6)为1.6%~5.9%。方法用于实际样品的分析,检出的氯硝柳胺的质量分数为0.580~2.18 mg·kg^(-1)。
文摘提出了在线固相萃取-高效液相色谱-串联质谱法(HPLC-MS/MS)同时测定家禽养殖废水中6种抗菌类药物(氟苯尼考、磺胺甲基嘧啶、痢菌净、氟哌酸、阿米卡星和头孢唑林钠)残留量的方法。取家禽养殖废水样品用纱布过滤,再用滤纸过滤,取滤液10.0 m L,通过Waters Oasis HLB固相萃取柱在线固相萃取,以Capcell PAK AG ODS C18色谱柱为固定相,以不同体积比的0.1%(体积分数)甲酸溶液-乙腈混合液为流动相进行梯度洗脱,采用电喷雾离子(ESI)源,在正离子(ESI+)扫描模式下进行多反应监测(MRM)模式质谱分析。结果表明,6种抗菌类药物的质量浓度在0.005~5.0 mg·L^(-1)内与对应的峰面积呈线性关系,检出限(3S/N)为0.018 3~0.072 2μg·L^(-1)。按照标准加入法进行回收试验,回收率为83.8%~105%,测定值的相对标准偏差(n=6)均小于5.0%。方法用于测定5个实际家禽养殖废水中6种抗菌类药物的残留量,检出量为16.09~277.14μg·L^(-1)。
