固相萃取超快速液相色谱-串联质谱同时测定熟肉制品中常用人工合成色素

目的建立一种同时测定熟肉制品中7种常用人工合成色素的固相萃取超快速液相色谱-串联质谱UFLC-MS/MS分析方法。方法熟肉制品用混合提取液提取后,用WAX固相萃取小柱净化,以乙腈和5 mmol/L乙酸铵水溶液为流动相,采用梯度洗脱方式在Shim-pack XR-ODS II色谱柱(75 mm×2.0 mm i.d.,2.2μm)上进行分离,以电喷雾负离子模式进行质谱分析。结果 7种人工合成色素在检测范围内均具有良好的线性关系(r>0.999),方法的定量限0.7~5.0μg/kg,熟肉制品的回收率88.2%~106.5%,RSDs 1.2%~5.0%。结论 UFLC-MS/MS法灵敏度高、重现性好、分析速度快,可用于熟肉制品中人工合成色素的确证检测。     

含乳食品中17种塑化剂的检测

目的采用固相萃取-超高效液相色谱-串联质谱技术(UPLC-MS/MS),建立含乳食品中17种塑化剂的检测方法。方法样品采用乙腈提取,经OASIS Prime HLB固相萃取柱净化。以BEH Phenyl(2.1 mm×100 mm×1.7μm)色谱柱进行色谱分离,以电喷雾电离(ESI)串联质谱多反应检测模式(MRM)进行监测,同位素内标标准曲线法定量。结果 17种塑化剂化合物在0.5~500μg/L浓度范围内呈良好的线性关系,R~20.9990,检出限为1~14μg/kg,加标回收率(n=6)为89.8%~119.0%,相对标准偏差(RSD)为3.62%~12.60%,具有良好的重现性。结论UPLC-MS/MS法简单、准确、灵敏度高,特别是样品前处理快捷简便,适用于含乳食品中17种塑化剂的检测。     

茶叶中黄曲霉毒素的高效液相色谱串联质谱法

目的建立茶叶中黄曲霉毒素B1、B2、G1和G2的高效液相色谱串联质谱(HPLC-MS/MS)法。方法样品经70%甲醇超声提取15 min,免疫亲和柱净化后,用ZORBAX Eclipse Plus C18色谱柱(2.1 mm×100 mm,1.8μm)进行分离,流动相为甲醇-0.1%甲酸水(体积比为45∶55),采用多反应监测(MRM)正离子模式进行检测。结果在0.5~50.0 ng/ml的线性范围内,所得4种黄曲霉毒素的回归方程均具有良好的线性关系(r≥0.999 5)。该方法检出限为0.02~0.04μg/kg,定量下限为0.07~0.13μg/kg;平均回收率为75.6%~98.5%,RSD为3.9%~7.1%。结论该方法简单、准确、灵敏度高,适用于茶叶中黄曲霉毒素B1、B2、G1和G2的批量检测。     

液相色谱-串联质谱检测鸡蛋中氟虫腈及其代谢物的残留量

目的建立一种检测鸡蛋中氟虫腈及其代谢物残留的液相色谱-串联质谱(LC-MS/MS)定量分析方法。方法优化检测条件:用乙腈进行样品提取,选择C18固相萃取小柱和无水硫酸镁对提取样品净化后进行液质联用检测。结果经过优化后液相条件:流动相由2mmol/L的甲酸铵水溶液和甲醇组成,采用梯度洗脱方式在C18反相色谱柱中进行分离,进样量为4μL。质谱条件:离子源采用ESI负离子,通过SRM模式对样品中氟虫腈及其代谢物进行定量检测。优化后,氟虫腈及其代谢物在0~20ng/mL质量浓度范围内线性关系良好,R2均>0.9993,检出限(S/N=3)和定量限(S/N=10)分别0.2~0.4μg/kg和0.66~1.32μg/kg。实际样品中添加4.0、20.0、40.0μg/kg 3个质量浓度水平下,平均回收率在76.60%~98.24%,相对标准偏差(RSD)为1.03%~3.41%,符合定量检测要求。结论该方法操作简便、灵敏度高,可满足鸡蛋中氟虫腈及其代谢物的检测要求。     

固相萃取-超快速液相色谱串联质谱测定食品中五氯酚

目的建立了食品中五氯酚的固相萃取-超快速液相色谱串联质谱分析方法。方法样品用8%三乙胺的乙腈水溶液(70/30,V/V)提取,用MAX固相萃取小柱净化。以乙腈和5 mmol/L乙酸铵(内含0.1%甲酸)为流动相,采用梯度洗脱方式在Shim-pack XR-ODS Ⅲ色谱柱(150 mm×2.0 mm,2.2μm)上进行分离,以电喷雾负离子模式进行质谱检测,内标法定量。结果五氯酚在0.5~50.0μg/L范围内具有良好的线性关系(r0.999),方法的定量限为0.4~0.5μg/kg,检出限为0.12~0.15μg/kg,样品的回收率为82.0%~108.0%,精密度为1.89%~5.09%(n=6)。结论该方法灵敏度高、重现性好,可用于多种食品中五氯酚的检测。     

高分子印迹固相萃取技术结合GC/MS法测定食用油中16种多环芳烃

目的建立一种分子印记固相萃取-气相色谱/质谱联用(MISPE-GC/MS)法测定食用油中16种多环芳烃(PAHs)的检测方法。方法样品经正己烷稀释后,于高分子印记固相萃取柱净化,正己烷淋洗除杂,二氯甲烷洗脱,洗脱液最终浓缩定容至200μL,采用气相色谱毛细管柱(30 m×0.25 mm×0.25μm)分离,选择离子模式进行扫描,同位素内标法定量。结果 16种多环芳烃在2~20μg/L范围内有很好的相关性,相关系数均大于0.998;检出限范围为0.1~0.6μg/kg;在2μg/kg和10μg/kg两个加标水平下,加标回收率范围为75.5%~125.2%(n=6),相对标准偏差均小于15%。结论 MISPE-GC/MS法选择性好,快速,净化效果好,灵敏度高,能够快速准确地测定食用油中16种多环芳烃。     

蔬菜和水果中杀菌剂的高效液相色谱-串联质谱检测法

目的建立高效液相色谱-串联质谱(LC-MS/MS)法定量测定蔬菜和水果中11种杀菌剂的方法。方法样品以快速样品前处理技术(Qu ECh ERS法)净化,经LC-MS/MS检测,以选择离子扫描(SIM)模式检测目标化合物的特征离子进行定性定量分析。结果 11种杀菌剂在测定的范围内线性关系良好(r0.999 0),方法的检出限为0.4~2.5μg/kg(S/N=3)。在加标水平为40、60、80μg/L时,方法的回收率为75.6%~108.2%,相对标准偏差为1.2%~7.5%。结论该方法前处理简单,分析时间短、选择性好和灵敏度高,适用于蔬菜和水果中杀菌剂的检测。     

超高效液相色谱-高分辨质谱法测定蜂蜜中14种农药残留

目的建立超高效液相色谱-高分辨质谱同时快速测定蜂蜜中14种农药残留的方法。方法样品采用1%甲酸乙腈提取,以N-丙基乙二胺(PSA)和C18作为吸附剂的分散固相萃取法(d-SPE)进行净化,以Accucore a Q C18色谱柱(2.6μm,2.1 mm×150 mm)进行色谱分离,通过高分辨质谱的全扫描/实时二级质谱扫描模式进行定性筛查和定量检测。结果 14种农药残留在一定浓度范围内呈良好的线性关系,相关系数(r)均大于0.998,定量限(LOQ)为0.6~6μg/kg。空白蜂蜜样品在LOQ、15和30μg/kg三个加标水平的平均回收率为80.3%~112.7%,相对标准偏差为0.4%~7.1%。结论该方法适合蜂蜜中农药多残留的快速筛查和定量。     

凝胶渗透色谱与气相色谱-串联质谱法检测蔬菜中15种有机氯农药残留

目的通过优化凝胶渗透色谱净化系统(GPC)及气相色谱-串联质谱(GC-MS/MS)技术参数,建立GPC与GC-MS/MS法检测蔬菜中15种有机氯农药残留的方法。方法蔬菜样品经乙腈溶剂提取,氮吹至近干,上GPC处理净化,样品净化后用GC-MS/MS法进行定性、定量分析。实验中比较2条不同凝胶柱及GPC流动相在不同流速下对净化效果的影响,同时比较2条不同毛细管柱的分离效果,根据实验结果,采用20 mm×400 mm凝胶柱、流量为3 ml/min为净化条件,选用中等极性毛细管柱TR-1701为分析色谱柱。结果本方法中,15种有机氯农药的浓度为0.005μg/ml~0.200μg/ml时,线性相关系数(r)≥0.990,定量限为0.000 04 mg/kg~0.001 60 mg/kg。对韭菜样品按0.005 mg/kg、0.025 mg/kg、0.100 mg/kg 3组水平进行加标试验,方法的精密度(RSD)为2.8%~12.0%,回收率为72.1%~104.1%。结论本方法检测样品的范围广、灵敏度高、定性可靠、定量准确,适合蔬菜中农药多残留的分析。     

液相色谱-串联质谱法同时测定面粉中5种镰刀菌毒素方法的建立

目的建立同时检测面粉中DON、15A-DON、3A-DON、ZEN、NIV5种镰刀菌毒素的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。方法用乙腈-水(84∶16)溶液提取样品,经净化柱净化后,氮气吹干,20%甲醇液定容,用UPLC-MS/MS进行测定。UPLC-MS/MS检测镰刀菌毒素的条件为梯度洗脱,流动相为0.3%氨水和乙腈;质谱采集模式为电喷雾正离子多反应监测模式。结果 5种镰刀菌毒素在5~1 000μg/L线性范围内呈线性关系良好(相关系数r值均0.99);检出限:DON、3A-DON、15A-DON均为0.4μg/kg,ZEN为0.3μg/kg,NIV为0.2μg/kg。不同加标水平的5种镰刀菌毒素回收率为70%~105%,相对标准偏差(RSD)为5.2%~8.9%。结论 UPLC-MS/MS法具有操作简单、灵敏度高、重现性好等特点,可同时检测面粉中5种镰刀菌毒素。     

医疗服务操作分类与编码的设计与应用简

医疗服务操作分类与编码是医学信息标准化的重要组成部分,是临床数据提取、分析和应用的基础。世界卫生组织及世界多国一直致力于开发、更新和维护此分类与编码。我国此前一直沿袭美国准备在2014年停止使用的ICD-9-CM-3（卷3）,中国需要结合国际主流设计思路,根据国情开发出适宜的多轴、一体化的医疗服务操作分类与编码体系。     

Adenocarcinoma of the stomach and esophagus and drinking water and dietary sources of nitrate and nitrite

We conducted a population-based case-control study of adenocarcinoma of the stomach and esophagus in Nebraska, U.S.A. Nitrate concentrations in public drinking water supplies were linked to residential water source histories. Among those using private wells at the time of the interview, we measured nitrate levels in water samples from wells. Dietary nitrate and nitrite were estimated from a food-frequency questionnaire. Among those who primarily used public water supplies (79 distal stomach, 84 esophagus, 321 controls), average nitrate levels were not associated with risk (highest versus lowest quartile: stomach OR=1.2, 95% CI [0.5-2.7]; esophagus OR=1.3, 95% CI [0.6-3.1]). We observed the highest ORs for distal stomach cancer among those with higher water nitrate ingestion and higher intake of processed meat compared with low intakes of both; however, the test for positive interaction was not significant (p=0.213). We did not observe this pattern for esophagus cancer. Increasing intake of nitrate and nitrite from animal sources was associated with elevated ORs for stomach cancer and with a significant positive trend in risk of esophagus cancer (P-trend=0.325 and 0.015, respectively). Larger studies with higher exposures to drinking water sources of nitrate are warranted to further evaluate N-nitroso compound precursors as risk factors for these cancers.     

Drinking water and dietary sources of nitrate and nitrite and risk of glioma

OBJECTIVE: Dietary nitrite has been associated with increased glioma risk; however, drinking water nitrate has not been extensively evaluated. METHODS: We conducted a population-based case-control study of adult glioma in Nebraska. Water utility nitrate measurements were linked to residential water source histories. We computed average nitrate exposure over a 20-year period. A food frequency questionnaire was used to assess dietary nitrate and nitrite. RESULTS: Increasing quartiles of the average nitrate level in drinking water were not significantly associated with risk (adjusted odd ratios: 1.4, 1.2, 1.3). Risk was similar among those with both higher and lower intakes of vitamin C, an inhibitor of N-nitroso compound formation. Dietary nitrite intake was not associated with risk. CONCLUSIONS: Our study does not support a role for drinking water and dietary sources of nitrate and nitrite in risk of adult glioma.     

黄体功能不健的调控机理

主要就引起卵巢黄体功能不健的因素 ,分别从激素调节、细胞因子 (VEGF、TNF α、BFGF、IFN γ、IGF)、C myc、Fas、SGP 2基因调控以及细胞连接、细胞粘附分子、NO等对卵巢功能的调节及对黄体细胞的凋亡影响进行阐述 ,认为卵泡发育不良、颗粒细胞、黄体细胞的凋亡与黄体功能不足有密切的关系。且多种细胞因子、基因表达产物参与此过程的调控。深入的研究这一调控机制 ,对于进一步了解卵巢卵泡生长发育、卵泡闭锁及黄体细胞凋亡的内在机制有重要意义     

浸润性和转移性膀胱癌的诊断和评价

一、膀胱癌的分级与分期 1.膀胱癌的组织学类型:尿路被覆的上皮统称为尿路上皮(urothelium).传统上将尿路上皮称为移行上皮(transitional epithelium).目前在文献和习惯上这两个名词常常被交替使用.膀胱癌的组织学类型包括尿路上皮癌、鳞状细胞癌和腺癌,其次还有较少见的转移性癌、小细胞癌和癌肉瘤等.     

Absorption and excretion of cholecalciferol and of 25-hydroxycholecalciferol and metabolites in birds

The absorption and excretion in vivo of cholecalciferol or 25-hydroxycholecalciferol (25-HCC) were determined in chicks (Gallus domesticus) and turkeys (Meleagris gallopavo). The overall net cholecalciferol or 25-HCC absorption in chicks and cholecalciferol in turkey poults was 66.5 +/- 3.3, 74.9 +/- 3.7 and 83.6 +/- 7.1% of the intake, respectively. The absorption of cholecalciferol or 25-HCC in chicks and turkeys occurred at the upper part of the intestine. 25-HCC, esters and non-polar metabolites of cholecalciferol or 25-HCC, and their polar metabolites, were secreted in the duodenum of chicks and turkeys but were partially reabsorbed at the upper part of the jejunum.     

环境中双酚A的污染及降解去除的研究进展

近10年来随着科学与社会的发展,环境雌激素污染日益引起人们的关注。双酚A是环境雌激素的一种,用途广泛,但具有多方面的毒性。对其毒理、污染及降解去除的研究已经成为国际上的研究热点。该文拟对上述几方面的研究进展情况作一简要介绍。