ICP—AES法测定钢铁样中硅,磷,锰,铬,镍,铜,铝

详细地研究了钢铁样中主量铁对７种被测定元素的干扰和被测定元素间的干扰情况，并研究了不同酸分解样品的效果，确定了用电感耦合等离子体发射光谱测定钢铁样中硅、磷、锰、铬、镍、铜和铝的方法。     

用超高灵敏度试剂四苯基卟啉反相高效液相色谱法同时测定微量铜、铅、锌和镉

 〕本文研究了四苯基卟啉和一些金属离子的络合反应条件和反应速度；研究了铜、铅、锌及镉离子和四苯基卟啉所形成的络合物的稳定性，并测定了它们的组成；研究了这些络合物的吸收光谱及同时测定这些金属离子的合适波长，确定光度检测的条件；研究了络合物的色谱行为和可能的干扰，确定了反相色谱分离条件。在上述研究的基础上提出同时测定这些金属元素的反相液相色谱法。方法快速，精密度好，变异系数在0.62—3.5％之间。最低检出量为0.04ngCd，0.16ngPb，0.20ngCu和0.005ngZn。本文提出的方法已成功地应用于锡基合金及电镀废水中铜、铅、锌和镉的测定，准确度好。     

聚合氯化铁中OH／Fe物质的量比的测定

讨论了测定聚合氯化铁中OH/Fe物质的量比的几种方法,确定用过量碱沉淀法测定聚合氯化铁中的OH/Fe物质量比;同时研究了影响测定的各种因素,找出了最佳的测定条件.通过对合成试样和未知试样的测定,结果表明方法无系统误差存在,结果准确、可靠.     

直接电导离子色谱法测定水和废水中的铬(Ⅵ)

研究了利用离子色谱测定地表水和电镀废水中的Cr(Ⅵ)。研究结果表明,离子色谱法测定Cr(Ⅵ),测定标准样品的相对误差低于2.5%,多次测定的相对标准偏差低于2.2%。在含有较高浓度的其他无机阴离子时,检测结果不受干扰,而且检出限为0.012mg/L。     

离子色谱法同时测定大米中的硫和氯

植物样品中硫和氯的测定,在常规分析中一般是分别取样测定。离子色谱法测定硫和氯虽有不少报道,但测定大米中的硫和氯尚未见到。本文研究了用离子色谱法同时测定大米中硫和氯的方法,此方法通过加入碳酸钠灰化样品、水提取、阳离     

晶态聚合物结构的X射线衍射分析及其进展

本文分结晶度的测定，微晶尺寸和点阵缺陷的测定，取向情况的测定等方面，阐述了使用Ｘ射线衍射分析研究聚合物晶体结构的各种方法及其进展。     

石墨探针原子化法测定土壤和煤飞灰中的钴

用试验优化设计研究了测定钴的条件,考察了某些元素对测定钴的干扰效应,建立了土壤和煤飞灰中钴的测定方法。     

新铜试剂-铜(Ⅰ)体系萃取原子吸收法间接测定微量硫氰酸根

本文研究了NCP-Cu(Ⅰ)·SCN-离子对的形成、萃取和测定条件;探讨了有机溶剂对测定灵敏度的影响。用于电镀厂排放水中微量硫氰酸根的测定,获得了满意的结果。     

钢中稀土相电化学特性及物相鉴定的研究

试验研究了人工合成的一系列钢中可能存在的稀土相在不同电解液中的化学和电化学行为;测定了各稀土相的极化曲线、稳定电位和活化电位值;研究了钢中各稀土相在电化学过程中的基本规律;确定了4种较好的电解液和电解制度,为定量提取钢中稀土相和测定稀土在钢中的固溶量提供了较好的方法。所测定的晶体学数据可供对稀土相的鉴定工作     

用埃铬青R和十六烷基三甲基溴化铵光度法测定钒

文献曾报导用铬天青S和十四烷基二甲基苄基氯化铵光度法测定钒,但只能在20分钟内稳定。王怀公则用邻苯二酚紫和CPC光度法测定钒。我们研究了用埃铬青R(ECR)和十六烷基三甲基溴化铵(CTAB)光度法测定钒的反应条件和络合物的组成;研究了试剂加入顺序与反应速度之间的关系,提出了对文献中关于反应速度问题的补充。该络合物     

基于拮抗作用检测除草剂的类囊体膜生物传感器研究

利用除草剂对植物类囊体束缚酶分解过氧化氢的拮抗作用,研制了一种快速检测痕量除草剂的电化学生物传感器.将植物类囊体用聚乙烯醇-苯乙烯吡啶(PVA-SbQ)光敏聚合剂在紫外光诱导下产生大分子网状结构进行包埋,制成生物敏感膜,并固定在铂电极表面.根据加入除草剂时类囊体膜束缚酶分解过氧化氢活性的变化,对除草剂进行测定.在含有1×10-3mol/LNaCl,5×10-3mol/LMgCl2和0.01mol/LH2O2的Tris-HCl缓冲溶液(pH=7.4)中,基于测量0.65V处H2O2氧化电流的变化,可以对下列浓度的除草剂进行定量检测:百草枯3×10-9～1.5×10-7mol/L,敌草龙1×10-8～3×10-7mol/L,扑草净4×10-8～3×10-6mol/L,阿特拉津1×10-7～5×10-6mol/L,莠灭净1×10-7～5×10-6mol/L.利用PVA-SbQ光聚合膜固定类囊体,能够使酶的活性在低温下保持数月.     

毛细管电泳-场强放大样品堆积法检测染发剂中的7种苯胺类物质

建立了毛细管电泳-场强放大样品堆积测定染发剂中4,4′-二氨基二苯甲烷、苯胺、邻甲氧基苯胺、对氨基苯甲醚、3,4-二甲基苯胺、间氨基苯酚、1-萘胺7种苯胺类物质的分析方法。在优化的缓冲溶液体系(0.15 mol/L NaH2PO4,0.015 mol/L 三乙醇胺, pH 2.3)下7种分析物在6.5 min内实现基线分离。考察了样品中添加的磷酸浓度和乙腈浓度、水柱长度、电动进样时间与电压对场强放大富集效率及重现性的影响。最佳的富集条件为: 水柱注入3.45 kPa(0.5 psi)×6 s,样品中添加40%(v/v)乙腈和0.6×10~3mol/L磷酸,进样电压与进样时间为10 kV×10 s。线性范围为3～1000 μg/L(R2＞0.996),检出限为0.26～2.75 μg/L,将已有方法的检测灵敏度提高了1～3个数量级。在2种市售黑色染发剂中均检测到间氨基苯酚,含量分别为7.32 mg/g和1.34 mg/g。平均加标回收率为74%～108%。该方法灵敏度高、快速、重现性好、成本低,可供多种样品基质中痕量苯胺类污染物及其他阳离子物质的测定借鉴使用。     

Automatic flow system titration based on multicommutation for spectrophotometric determination of total acidity in silage extracts

A multicommutated flow titration procedure is proposed for the spectrophotometric determination of total acidity in silage extracts. The flow network comprises a set of 3-way solenoid valves, computer-controlled to provide facilities to handle the titrand, titrant, and carrier solutions by using a single pumping channel. The procedure is based on the volumetric fraction variation approach that maintains the same volume of titrand solution and varies the titrant solution step by step, to provide determination without the use of an analytical curve. The procedure is implemented by using phenolphthalein as an external indicator; the proposed algorithm was able to titrate silage extracts presenting different color intensities. Sample solutions with concentrations ranging from 10(-3) to 10(-1) mol/L total acidity could be analyzed by using 10(-2) mol/L sodium hydroxide as the titrant solution. Other advantages include a relative standard deviation of <1.0% (n = 4) for a typical silage extract solution containing 26 mmol/L total acidity; an analytical throughput of 16 determinations per hour was also achieved. Accuracy was assessed by processing a set of silage extract solutions and comparing the results with those obtained by using the conventional potentiometric titration procedure. No significant difference at the 95% confidence level was observed.     

修饰铂电极上Bi(Ш)的示波双电位滴定法

制备了Bi(Ⅲ)修饰铂电极,用循环伏安法表征了Bi(Ⅲ)在电极上的吸附特性,探讨了电极的响应机理。 通过优化实验条件,建立了一种测定Bi(Ⅲ)的示波双电位滴定法。 在0.1 mol/L的硝酸溶液中(pH=1.0),用制备的修饰铂电极作为双指示电极,以EDTA标准溶液滴定Bi(Ⅲ),利用示波器屏幕上荧光点的显著最大位移指示滴定终点。 Bi(Ⅲ)在1.19×10-4～1.44×10-2 mol/L时,回收率为99.8%～100.1%,检出限(S/N=3)为1.0×10-4 mol/L。 该修饰电极具有良好的稳定性和重现性,在含有1.0×10-2 mol/L Bi(Ⅲ)的溶液中,连续7次测定,所得终点电位值均在100 mV左右,其相对标准偏差(RSD)为0.04%。 应用该方法测定含铋样品,RSD值(n=7)小于0.25%,回收率为99.5%～100.5%,测定结果与指示剂法测定值相符。     

微透析取样-流动注射电化学检测测定表柔比星与牛血清白蛋白体外结合参数

建立了微透析取样-流动注射电化学检测法测定表柔比星与牛血清白蛋白体外结合参数的方法。流动相为pH 3.0的0.1 mol/L H3PO4-NaH2PO4缓冲液(含3.4×10﹣5mol/L Na2EDTA),流速为0.3 mL/min。电化学检测的工作电极为玻碳电极,工作电位为0.52V。表柔比星浓度在5.0×10-5～5.0×10-7 mol/L范围内与峰电流呈良好的线性关系,其相关系数为0.9997,检出限为2.0×10-7mol/L。结合微透析取样,实现了对表柔比星与牛血清白蛋白结合参数的测定。表柔比星与牛血清白蛋白的体外结合符合Scatchard曲线,结合常数和结合位点数分别为2.41×104L/mol和4.02。     

酸性媒染紫-示波计时电位法测定天然水和饮用水中铝

报道酸性媒染紫（ＳＶＲＳ）－示波计时电位法测定天然水及饮用水中铝。在０．８５ｍｏｌ／Ｌ　ＮＨ３·Ｈ２Ｏ－ＮＨ４Ｃｌ－５×１０－５ｍｏｌ／Ｌ ＳＶＢＳ（ｐＨ８．８）底液中,Ａｌ－ＳＶＲＳ络合物在－１．０５Ｖ电位处产生灵敏切口,切口深度与铝浓度成正比,可用于定量分析。线性范围为１×１０－７～６×１０－６ｍｏｌ／Ｌ． ＲＳＤ为５．５％ （ｎ＝１０,２×１０－７ｍｏｌ／Ｌ）,检测限为５×１０－８ｍｏｌ／Ｌ。本法特点为：在碱性条件下,无需加热,无需通氮除氧,无需预富集,大大减少了分析时间。仪器简单,方法灵敏准确,特别适用于天然水和饮料中Ａｌ的分析。对实际水样进行了分析,与ＩＣＰ／ＡＥＳ法所测结果基本一致。     

2'-硼酸基苯甲醛-7-(8-羟基-5-磺酸基)喹啉腙衍生物的合成及对Pb2+的识别

合成了2', 3'和4'-硼酸基苯甲醛-7-(8-羟基-5-磺酸基)喹啉腙衍生物(化合物1~3), 研究了硼酸基团取代位置对主体分子识别金属离子客体性能的影响, 比较了不同主体分子与Pb2+结合能力的差异. 研究结果表明, 在pH=7.0的KH2PO4-NaOH缓冲溶液中, 3种腙衍生物对Pb2+均具有选择性识别作用, 主客体分子间形成1∶1型的发光配合物. 其中邻位取代的化合物1与Pb2+的结合能力比化合物2和3强, 配合物1-Pb2+的最大发射波长为477 nm, 稳定常数为1.1×103 L/mol. 其它金属离子如Cu2+, Mn2+, Mg2+, Fe2+, Ca2+, Co2+, Ni2+, Hg2+, Cd2+和Ag+ 等对主体分子荧光光谱的影响较小. 同时, 荧光强度的变化值与Pb2+浓度在0.36~10 μmol/L范围内呈现良好的线性关系, 相关系数R=0.9976(n=16), 检出限为0.23 μmol/L. 将此方法用于环境水样中Pb2+的测定, 回收率为92%~108%.     

Gran电位滴定法测定乳酸环丙沙星

介绍了乳酸环丙沙星测定的Gran电位滴定法。采用Gran线性函数进行电位滴定,经图解外推或线性回归处理求出计量点,可直接用于测定乳酸环丙沙星原料药的含量。该法用于多批原料药的测定,结果与药典法基本一致。     

Determination of low-aliphatic aldehydes indoors by micellar electrokinetic chromatography using sample dissolution manipulation for signal enhancement

This work describes a novel approach for the analysis of selected aldehydes (formaldehyde, acetaldehyde, propionaldehyde, and acrolein) and acetone in environmental samples using micellar electrokinetic chromatography (MEKC). The method is based on the reaction of carbonyl compounds with 3-methyl-2-benzothiazoline hydrazone (MBTH) that gives an azine intermediate with maximum absorbance at 216 nm. A systematic evaluation of sample dissolution medium was conducted as a means to enhancing sensitivity. In the best condition, samples were dissolved in 0.030 mol.L(-1) tetraborate solution. This condition presented enhancement factors in the range of 35-54 for the aldehydes under investigation, computed as the improvement of the concentration limits of detection (LODs) with reference to the sample dissolved in pure water. The running buffer was 0.020 mol.L(-1) tetraborate, pH 9.3, containing 0.050 mol.L(-1) sodium dodecyly sulfate (SDS). The overall methodology presented several advantages over established methods for aldehydes. Worthy mentioning that MBTH is available in high purity degree, dispensing laborious reagent purification procedures. A few method validation parameters were determined revealing good migration time repeatability (< 2.5% coefficient of variation, CV) and area repeatability (< 4% CV), excellent linearity (20-120 micro g/L, r > 0.995) and adequate sensitivity for environmental applications. The LODs with respect to each single aldehyde were in the range of 0.54-4.0 micro g.L(-1) and 11 micro g.L(-1) for acetone. The methodology was applied to the determination of aldehydes indoors. Samples were collected in an impinger flask containing 0.05% MBTH solution, at a flow rate of 0.80 L.min(-1), during 2.5 h, at different times during the day. The most abundant carbonyls in the samples were acetone, followed by formaldehyde and acetaldehyde, with estimate peak concentrations of 452, 5.2 and 2.2 ppbv, respectively.     

Differential amperometric determination of hydrogen peroxide in honeys using flow-injection analysis with enzymatic reactor

Hydrogen peroxide (H2O2) present in honey was rapidly determined by the differential amperometric method in association with flow-injection analysis (FIA) and a tubular reactor containing immobilized enzymes. A gold electrode modified by electrochemical deposition of platinum was employed as working electrode. Hydrogen peroxide was quantified in 14 samples of Brazilian commercial honeys using amperometric differential measurements at +0.60V vs. Ag/AgCl((sat)). For the enzymatic consumption of H2O2, a tubular reactor containing immobilized peroxidase was constructed using an immobilization of enzymes on Amberlite IRA-743 resin. The linear dynamic range in H2O2 extends from 1 to 100 x 10(-6) mol L(-1), at pH 7.0. At flow rate of 2.0 mL min(-1) and injecting 150 microL sample volumes, the sampling frequency of the 90 determinations per hour is afforded. This method is based on three steps involving the flow-injection of: (1) the sample spiked with a standard solution, (2) the pure sample and (3) the enzymatically treated sample with peroxidase immobilized. The reproducibility of the current peaks for hydrogen peroxide in 10(-5) mol L(-1) range concentration showed a relative standard deviation (R.S.D.) better than 1%. The detection limit of this method is 2.9 x 10(-7) mol L(-1). The honey samples analyses were compared with the parallel spectrophotometric determination, and showed an excellent correlation between the methods.