氢化物原子荧光法测定水中硒优化条件选择

参考我国卫生部生活用水卫生规范及检验规范，采用模糊正交设计法，建立氢化物原子荧光法测定水中硒的优化实验方法。根据实验优化条件进行水中硒测定，硒浓度在0-0．20mg／L范围内有良好线性关系，r=0．9997，检出限为0．78μg／L，相对标准偏差为2．396～7．9％，回收率为96％～105％。利用该优化的实验条件进行氢化物原子荧光法水中硒测定，方法更加准确、灵敏、稳定。     

应用氢化物原子荧光法同时测定蔬菜中的砷和汞

采用氢化物发生-原子荧光法同时测定蔬菜中的砷和汞，具有操作简便，灵敏度高、准确度高、基体干扰少、节省试剂等特点。方法的回收率为：砷87．25％-113．15％，汞89．0％-106．5％；检出限为：砷0．13μg／L，汞0．009μg／L；线性范围为：砷0．5-150μg／L，汞0．2-50μg／L；相关系数达0．9995以上。     

用原子荧光法测定水中硒的不确定度

本文根据测量不确定度评定与表示理论,用原子荧光法测定水中痕量硒的不确定度,得出该法测定水中痕量硒的扩展不确定度U=1.3μg/L。     

氢化物发生原子荧光法测定水中痕量砷和汞

本文研究了用氢化物发生原子荧光法测水中痕量砷和汞。此法是在盐酸介质中，以硼氢化钾作还原剂，将被测元素转化为挥发性氢化物，以高纯氩气作为载气将挥发性氢化物从母液中分离，并导入石英炉原子化器中原子化。以特种空心阴极灯作激发光源，荧光强度值在一定范围内与被测元素的浓度成正比。该法灵敏度高，精密度好，准确度高，As和Hg的检出限分别为0．0618和0．0158μg／L。     

应用双道原子荧光光度计同时测定水中砷和锑

氢化物发生原子荧光光度法同时测定水中砷和锑,在优化实验条件下,砷和锑的检出限可分别达到:As:0.020μg/L,Sb:0.041μg/L。     

应用双道原子荧光光度计同时测定水中砷和硒

氢化物发生原子荧光光度法同时测定水中砷和硒,在优化实验条件下,砷和硒的检出限可分别达到:As:0.026μg/L,Se:0.045μg/L。     

应用氢化物原子荧光光谱法测定粮食中的硒

应用氢化物原子荧光光谱法测定粮食中的硒，具有操作简单、快速、基本干扰少，灵敏度高等优点，实用性强。方法检出限为0．3μg／L，线性范围为0-360μg／L，方法回收率为84．6-110％。     

氢化物发生原子荧光法检测打印机喷墨中的砷和汞

建立了双道原子氢化物发生原子荧光法，并检测打印机喷墨中的砷(As)和汞(Hg)，As和Hg的检测限分别为：0．0453μg／L，0．0108μg／L，精密度(n=11)：1．80％和1．58％，回收率分别为：99．31％～106．91％，72．40％～128．15％。该法快速、灵敏、准确。     

原子荧光光谱法快速检测化妆品中的砷和汞

介绍原子荧光光谱法用于化妆品中砷和汞的快速检测方法，用HN03一H202消化样品，选择了最佳测试条件，砷和汞的线性检测范围分别是0—200μg／L和0-20μg／L，方法检出限分别为0．0213μg／L和0，0032μg／L，样品加标回收率分别在96．4％-100．5％和93．5％-101．0％之间。本法灵敏度高、操作简便、结果准确。     

应用氢化物-原子荧光法测定大蒜中硒

应用氢化物-原子荧光法测定大蒜中硒，选定了其最佳测定条件，对还原剂的浓度、酸的种类和浓度、干扰元素的消除等进行了研究。同时应用氢化物-原子荧光法和氢化物-原子吸收法进行了仪器比对实验。结果表明，氢化物-原子荧光法测定大蒜中硒，其方法检出限1．112μg／L，相对标准偏差(RSD)2．6％，具有经济实用、操作简便、快速、灵敏度和选择性好、准确等优点。     

离子色谱法测定牛乳中硝酸盐的不确定度评定

目的:全面地分析离子色谱法测定牛乳中硝酸盐的不确定度来源及其影响因素。方法:通过建立数学模型,对测量过程中的不确定度进行逐层分析与合成,采用最小二乘法对外标曲线拟合的不确定度进行评定。结果:离子色谱法测定牛乳中硝酸盐的相对扩展不确定度为2.42%(k=2)。结论:本文不确定度的评定方法在实际工作中具有较强的实用价值。     

Analysis of specific lipid metabolites in cord blood of patients with gestational diabetes mellitus

This work aimed to clarify the interaction between the fetus and pregnant patients with gestational diabetes mellitus (GDM), the lipid metabolomics analysis of the fetal umbilical cord blood of GDM patients and normal pregnant women were performed to screen out the specific lipid metabolites for pathogenesis of GDM. From 2019–2020, 21 patients with GDM and 22 normal pregnant women were enrolled in Hexian Memorial Hospital, Panyu District, Guangzhou. The general information such as weight, height, age, body mass index (BMI) before pregnancy were analyzed. Non-targeted metabonomic detection and analysis were performed in umbilical cord plasma using LC-MS method. The age, BMI, delivery methods, and infant weight were different between GDM and control. There were 167 lipid metabolites in umbilical cord blood associated with GDM. Among them, 158 upregulated and 9 downregulated in GDM. There were 13 dysregulated metabolites with C < 30, including Lyso-phosphatidyl-colines LPC 16:0, 18:2, 18:1, 18:0, 20:4 and 22:6, glycerophosphocholines PC O-16:1, oleoylcarnitine CAR 18:2 and 18:1, dihexosylceramides Hex2Cer 13:0;2O, phosphatidylethanolamine PE O-22:6_2:0 and PE O-22:6_3:0 and sphingomyelin SM 8:0; 2O/11:0. Those metabolites were associated with glycerophospholipid metabolism and sphingolipid metabolism. Therefore, Lyso-phosphatidyl-colines, glycerophosphocholines, oleoylcarnitine, dihexosylceramides, phosphatidylethanolamine, and sphingomyelin were main lipid metabolites of GDM, which might be used for diagnosis and treatment of GDM.     

生物芯片技术在食品安全检测中的应用前景

背景:全球食品安全形势十分严峻。目的:介绍生物芯片技术在食品安全检测方面的应用进展。方法:文献调研法,案例分析法。结果:提出生物芯片技术应用存在的问题及发展前景。结论:随着生命科学、信息技术以及分子生物技术的发展,生物芯片技术在食品安全检测中有广泛的应用前景。     

流式细胞技术(FCM)在人乳腺癌耐药细胞系耐药逆转研究中的应用

目的:人乳腺癌耐药细胞系(MCF-7/ADR)经不同逆转方法作用后,对耐药逆转结果进行检测,寻找最佳逆转方法。方法:用流式细胞仪,分别对MCF-7及经不同逆转剂作用后MCF-7/ADR进行检测。结果:经流式细胞仪检测,P-170表达:MCF-7为11.4％,MCF-7/ADR为99.2％,不同逆转剂作用细胞后各实验组P-170表达均大幅度下降。经PI染色后,不同逆转剂逆转MCD-7/ADR的细胞周期无明显变化。结论:异博定结合干扰素及加温的方法,逆转效果最佳。     

沱茶中茶多酚的分析与鉴定

用索氏提取器以三氯甲烷为萃取剂,在95 ℃下从沱茶中提取茶多酚。用旋转蒸发器将滤液浓缩,有机相中加入三氯甲烷(V(三氯甲烷):V(浓缩液)=3:1)将咖啡因萃取分离、去除。水相中加入乙酸乙脂(V(乙酸乙酯):V(水)=3:1)将沱茶提取物萃取分离。以硅胶G作填充剂,以乙酸乙酯(V(乙酸乙酯):V(乙醚)=4:1)为洗脱剂进行柱层析。用傅里立变换-红外光谱法(FT/IR)测定沱茶提取物待测组分的红外光谱图,提供官能团的有关信息。确定待测组分的可能结构;应用气相色谱-质谱法(GC/MS)对其进行分析与鉴定,由电子电离源质谱(EI/MS)获得待测组分的质谱图和相关数据,进而对子离子裂解途径和特征离子进行辅助解析,确证待测组分为茶多酚。为开发利用沱茶提供了科学依据。     

Fifty years of nucleophilic substitution in the gas phase

Bimolecular nucleophilic substitution () reactions have become a model system for the investigation of structure–reactivity relationships, stereochemistry, solvent influences, and detailed atomistic dynamics. In this review, the progress during five decades of experimental and theoretical research on gas phase reactions is discussed. Many advancements of the employed methods have led to a tremendous increase in our understanding of the properties and the dynamics of these reactions. For reactions involving six atoms a quantitative agreement of the differential reactive scattering cross sections has already been achieved, in the future it is expected that even larger polyatomic reactions systems become tractable. Furthermore, studies with higher precision, improved reactant control, and a more accurate theoretical treatment of quantum effects are envisioned.     

Significant progress in solution of nonlinear equations at displacement of structure and heat transfer extended surface by new AGM approach

In this paper, we aim to promote the capability of solving two complicated nonlinear differential equations: 1) Static analysis of the structure with variable cross section areas and materials with slope-deflection method; 2) the problem of one dimensional heat transfer with a logarithmic various surface A(x) and a logarithmic various heat generation G(x) with a simple and innovative approach entitled “Akbari-Ganji’s method” (AGM). Comparisons are made between AGM and numerical method, the results of which reveal that this method is very effective and simple and can be applied for other nonlinear problems. It is significant that there are some valuable advantages in this method and also most of the differential equations sets can be answered in this manner while in other methods there is no guarantee to obtain the good results up to now. Brief excellences of this method compared to other approaches are as follows: 1) Differential equations can be solved directly by this method; 2) without any dimensionless procedure, equation(s) can be solved; 3) it is not necessary to convert variables into new ones. According to the aforementioned assertions which are proved in this case study, the process of solving nonlinear equation(s) is very easy and convenient in comparison to other methods.     

导管室高值耗材信息化管理的实践

目的:探讨信息化管理在导管室高值耗材管理中的应用及效果。方法:采用HIS、SPD和红会三大软件系统,对高值耗材进行信息化管理。采用信息化的管理方法,实现了对导管室高值耗材管理的规范化、统一化和专业化。随机对15名相关人员进行满意度调查,将2018年7月-8月为传统管理模式,2019年1月-8月为信息化管理模式,了解2组管理模式对高值耗材的遗失、漏收、错收进行比较。结果:在满意度及使用方便度在2组管理模式方面比较具有统计学意义(P﹤0.05)结论:信息化管理高值耗材克服传统管理模式的弊端,使高值耗材管理更科学、更专业、更精准。     

荧光分光光度法测定滴眼液中萘甲唑林的含量

目的 :荧光分光光度法测定滴眼液中萘甲唑林的含量。方法 :激发波长2 81nm ,发射波长 32 7nm ,狭缝 5nm ;光电倍增管增益 :低 ;时间扫描速度 10nm/min。结果 :萘甲唑林在 10 0～ 5 0 0ng/mL范围内线性关系良好。回归方程Y =2 38+175 7X　r=0 9998。萘甲唑林滴眼液及淡泪净滴眼液的 3种浓度平均回收率 (n =9)分别为10 0 36 % ,10 0 0 3% ;RSD分别为 0 2 6 % ,0 2 7%。结论 :本法专属性强 ,结果准确。可用于滴眼液中萘甲唑林的含量测定。     

HPLC法测定活血壮筋丸中血竭素的含量

目的:HPLC法对活血壮筋丸中血竭素含量的测定。方法:Kromasil C_(18)(4.6mm× 250mm,5 μ m)为色谱柱,乙腈: 0.05mol/L磷酸二氢钠溶液(35 : 65)为流动相;流速:1.0mL/min;检测波长:440nm,柱温40℃。结果:血竭素浓度在5.50一27.48 μ g/ mL之间线性关系良好,平均回收率96.62%,RSD=1.1%,结论:该方法简单、可靠、专属性强,可用于活血壮筋丸的质量控制。