溶剂浮选吸光光度法测定痕量苯胺

本实验制定了以溴化十六烷基吡啶（ＣＰＢ）为捕收剂，捕收苯胺与ＮａＮＯ＿２重氮化并与Ｒ盐（２－萘酚－３，６－二磺酸钠）偶合而成的有色染料，以正丁醇为有机溶剂的溶剂浮选吸光光度法测定痕量苯胺的方案。其表观摩尔吸光系数可达６．４４×１０~６Ｌ·ｍｏｌ~（－１）·ｃｍ~（－１），测定浓度为４．９７６·１０~（－３）μｇ／ｍＬ的苯胺，５次测定的相对标准偏差为３％。     

氧极谱催化波法测定二苯胺

本文报道一种极谱测定二苯胺的新方法,它是基于二苯胺引起的氧极谱催化波.这个氧极谱催化波是由于二苯胺催化了电生超氧离子O_2~(-)的歧化反应产生的.本方法简单方便,有良好选择性.应用本方法测定了化工原料二苯胺的含量,结果令人满意.     

稀土三元络合物的极谱研究 Ⅱ．Eu（Ⅲ）－Cit－Ap体系稳定常数的测定

本实验用直流极谱法研究了Ｅｕ（Ⅲ）－Ａｐ，Ｅｕ（Ⅲ）－Ｃｉｔ二元体系和Ｅｕ（Ⅲ）－Ｃｉｔ－Ａｐ三元体系的极谱行为，在μ＝０．１（ＮａＮＯ３），ｔ＝２５±０．２℃条件下，电极过程为准可逆；测定了该条件下二元及三元络合物的稳定常数，讨论了三元络合物的有关形成条件。     

基于亚硝化反应的极谱法测定亚硝酸根的研究

提出了一种基于在酸性介质中甲基紫与亚硝酸根发生亚硝化反应，极谱法测定亚硝酸根的新体系。亚硝化产物在－０．７５Ｖ（ｖｓ．ＳＣＥ）处２．５次微分波的波高与ＮＯ２－的质量浓度在２．０×１０－３～２．０×１０－２ｍｇ／Ｌ（Ｓ＝４μＡ），４．０×１０－３～１．６×１０－１ｍｇ／Ｌ（Ｓ＝０．０２ｍＡ）范围内成直线关系。该法重复性好，且大多数常见的阴、阳离子不干扰，用于污水中痕量ＮＯ２－的测定，结果满意。     

稀土三元络合物的极谱研究：II.Eu（Ⅲ）—Cit—Ap体系稳定常数的测定

本实验用直流极谱法研究了Ｅｕ（Ⅲ）－Ａｐ，Ｅｕ（Ⅲ）－Ｃｉｔ二元体系和Ｅｕ（Ⅲ）－Ｃｉｔ－Ａｐ三元体系的极谱行为，在μ＝０．１（ＮａＮＯ３），ｔ＝２５±０．２℃条件下，电极过程为准可逆；测定了该条件下二元及三元络合物的稳定常数，讨论了三元络合物的有关形成条件。     

钴(Ⅱ)-β-巯基丙酸-NaNO_2体系的极谱催化波研究

在ｐＨ３．８的Ｈ２ＳＯ４－ＮＨ４Ａｃ介质中，Ｃｏ（Ⅱ）－β－巯基丙酸（ＭＰＡ）－ＮａＮＯ２体系产生－灵敏的极谱催化波，峰电位在－０．８４Ｖ（ｖｓ．ＳＣＥ），钴浓度在０．０２～１００ｎｇ／ｍＬ范围内与峰电流呈线性关系。检出限为０．０１ｎｇ／ｍＬ。本文对极谱波的性质和机理进行了初步探讨。本法用于土壤中总钴和有效钴的测定，结果满意。     

钴（Ⅱ）—β—巯基丙酸—NaNO2体系的极谱化波研究

在ｐＨ３．８的Ｈ２ＳＯ４－ＮＨ４Ａｃ介质中，Ｃｏ（Ⅱ）－β－巯基丙酸（ＭＰＡ）－ＮａＮＯ２体系产生－灵敏的极谱催化波，峰电位在－０．８４Ｖ（ｖｓ．ＳＣＥ）钴浓度在０．０２～１００ｎｇ／ｍＬ范围内与峰电流呈线性关系，检出限为０．０１ｎｇ／ｍＬ。本文对极谱波的性质和机理进行了初步探讨，本法用于土壤中总钴和有效钴的测定，结果满意。     

高效液相色谱法研究水溶性杯[8]芳烃与二苯胺磺酸钠的相互作用

采用高效液相色谱法研究了水溶性的对二甲氨甲基杯[ 8 ]芳烃(以下简称杯胺)与二苯胺磺酸钠的相互作用。以水溶性杯胺作流动相添加剂,考察了二苯胺磺酸钠在ODS柱上的色谱保留行为。实验发现,随着杯胺浓度的增大,二苯胺磺酸钠的保留时间逐渐延长,这是由于杯胺与溶质二苯胺磺酸钠形成了包结物的缘故。一方面二苯胺磺酸钠易电离,在ODS柱上保留弱;另一方面,由于杯胺对二苯胺磺酸钠的包结作用,降低了其极性,疏水性增强导致保留时间增加。其包结常数测定为1. 17×104 L/mol,包结比为1∶1,这与荧光法测定值2. 0×104 L/mol一致。同时考察了流动相的添加剂浓度、pH值等因素对二苯胺磺酸钠的保留行为的影响。实验表明,杯胺与二苯胺磺酸钠之间主要存在疏水作用和静电作用。     

痕量苯胺的单扫描极谱法测定

１引言环境水样中痕量苯胺的测定多采用偶氮化色法，利用苯胺偶氮盐与羟基化合物偶合生成的偶氮化合物的吸附波间接测定苯胺的方法已有报道。作者观察到，在氨水－氯化铵介质中，８－羟基喹啉与苯胺重氮盐偶合生成的偶氮化合物在滴汞电极上于－０．７４Ｖ（ｖｓ．ＳＣＥ）处产生－灵敏的导数极谱波，苯胺浓度在０．００８～１．４０ｍｇ／Ｌ范围内与波高呈良好的线性关系，可用于痕量苯胺的测定，方法用于污水中痕量苯胺的测定，结果令人满意。２实验部分２．１仪器与试剂ＪＰ－２型示波极谱仪；三电极体系导数档；苯胺标准溶液：１００与１…     

二甲苯蓝FF分光光度法测定微量亚硝酸根

研究了在稀盐酸介质中微量亚硝酸根与二甲苯蓝ＦＦ发生的亚硝化反应，建立了测定微亚硝酸极的新方法，方法的线性范围为０．２×１０＾－６～１５×１０＾－６ｇ／２５ｍｌＮＯ＾－２其Ｓａｎｄｅｌｌ灵敏度为９．１５×１０＾－１０ｇ／ｃｍ＾２，方法已用于水微量亚硝酸根的测定，并对反应机理进行了初步探讨。     

由氯化钠制硝酸钠的转化法研究

我国硝石矿很少,硝酸钠主要靠合成法生产,即用纯碱(或烧碱)溶液吸收硝酸“尾气”而得:     

Development of a flow-through optosensor for determination of Co(II)

A flow-through optical fibre chemical sensor for the determination of Co(II) at trace level using immobilised 2-(4-pyridylazo)resorcinol (PAR) as the reagent phase is proposed. PAR is physically adsorbed onto XAD-7. This method provided a great sensitivity and simplicity with wide linear response range from 1x10(-2) to 1x10(3)ppm and detection limit of 20ppb. This method also showed a reproducible result with relative standard deviation (R.S.D.) of 1.78% and response time of approximately 5min. The response towards Co(II) was also reversible using acidified KCl as the regenerating solution. Interference studies showed that Cr(III) significantly interfered during the determination. Excellent agreement with reference to inductively coupled plasma optical emission spectroscopy (ICPOES) method was achieved when the developed sensor was applied for determination of Co(II) in aqueous samples.     

Standard addition method applied to solid-state stripping voltammetry: determination of zirconium in minerals and ceramic materials

An application of the standard addition method to stripping voltammetry of solid materials immobilized in inert electrodes is described. The method allows the determination of the mass fraction of a depositable metal M in a material on addition of known amounts of a standard material containing M to a mixture of that material and a reference compound of a second depositable metal, R. After a reductive deposition step, voltammograms recorded for those modified electrodes immersed in a suitable electrolyte produce stripping peaks for the oxidation of the deposits of M and R. If no intermetallic effects appear the quotients between the peak areas and the peak currents for the stripping oxidation of M and R vary linearly with the mass ratio of the added standard and the reference compound, thus providing an electrochemical method for determining the amount of M in the sample. The method has been applied to the determination of Zr in minerals, ceramic frits, and pigments, using ZnO as reference material and ZrO₂ as the standard.     

不同基体改进剂对石墨炉原子吸收法测定土壤和沉积物中铊的影响

应用Pd(NO3)2-抗坏血酸(Vc)基体改进剂,建立了石墨炉原子吸收法(GFAA法)测定土壤和沉积物样品中铊。针对土壤和沉积物复杂基体,GFAA法测定铊元素主要受到氯离子的干扰,文中研究了常见基体改进剂(包括NH4NO3,(NH4)2SO4,La(NO3)3,Mg(NO3)2,Vc,Pd(NO3)2,Pd(NO3)2-Vc)对氯离子的抑制效果。通过研究不同基体改进剂测定含氯铊标准溶液的吸收曲线,探讨出基体改进剂测定铊的作用机理。以土壤或沉积物标准物质为研究对象,优化了应用Pd(NO3)2-Vc测定铊的灰化温度、基改剂浓度以及原子化温度。在最佳实验条件下,通过比较有无基体改进剂条件下,采用GFAA法测定不同土壤和沉积物中铊的精密度和准确度,实验结果表明,应用Pd(NO3)2-VC基体改进剂,测定土壤和沉积物标准物质中铊的测定结果都在标准值范围之内,6次平行测定的相对标准偏差范围为2.8%~8.4%,用于测定实际土壤和沉积物样品加标回收率为128.0%和92.9%。     

光度检测离子色谱法测定大豆中的植酸

本文介绍了用光度检测离子色谱法分离分析植酸的适宜条件。以NaNO_3和HNO_3为淋洗液,用磺基水杨酸和三氯化铁为柱后衍生试剂,使用国产YSA型阴离子分离柱分离和测定了大豆中的植酸,得到满意的结果。     

Analysis of grass silage from Northwestern Spain by near-infrared reflectance spectroscopy

Near-infrared reflectance spectroscopy (NIRS) was evaluated for the determination of protein, crude fiber (CF), acid detergent fiber (ADF), and neutral detergent fiber (NDF) in grass silage. Calibration equations were based on analyses of 366 samples of grass silage produced in Northwestern Spain over 4 consecutive years (1992-1995) and validated by analyses of a set of 72 silage samples harvested during 1996. Dried and ground samples were analyzed by chemical and NIRS procedures. The spectral data were analyzed by regression against a range of chemical parameters, using modified partial least-squares (MPLS) multivariate analysis in conjunction with different mathematical treatments of the spectra. For each parameter, the optimum calibration was evaluated on the basis of the coefficient of multiple determination (R2), the coefficient of simple correlation (r2), the standard error of calibration (SEC), the standard error of cross-validation (SECV), and the standard error of validation (SEV). R2 and r2 were >0.90; SEC values were 0.58, 1.04, 1.40, and 1.75; SECV values were 0.64,1.15,1.50, and 2.04; and SEV values were 0.56,1.02, 1.42, and 1.80 for protein, CF, ADF, and NDF, respectively. The ratio of the standard deviation of the reference data to the SEV was >3.0 for each of the 4 parameters, which indicates that the equations can be used in routine analysis.     

均配型三[2-(二甲胺基)苄基]钕配合物的合成、表征及在催化L-丙交酯聚合中的应用

在无水无氧的条件下,利用2-(二甲胺基)苄基钾盐KR(R=CH2C6H4-NMe2-o)与三氯化钕反应制得相应的均配型的三[2-(二甲胺基)苄基]钕稀土配合物NdR3,并培养出单晶。通过元素分析、IR和X-射线单晶衍射表征了其结构,配合物NdR3属单斜晶系,P21/c空间群,a=1.710 01(19)nm,b=0.949 54(9)nm,c=1.678 27(18)nm,β=110.776(2)°,Z=4,V=2.547 8(5)nm3,R=0.037 1,wR=0.079 2。该配合物的中心金属Nd为六配位,几何构型为三棱柱型。配合物NdR3能够有效地催化L-丙交酯的开环聚合。     

Investigation on the Decomposition of Carboplatin in Infusion Solutions

 An integrated solid-phase spectrophotometry/flow injection analysis (FIA) method is proposed for the determination of the synthetic colorant matter Ponceau 4R (P4R) in the presence of its unsulfonated derivative 2-hydroxy-1-[(naphthalenyl)azo] naphthalene (N2N). The procedure is based on the measurement of P4R at λ = 508, followed by retention and preconcentration of the low level concentration of N2N on a C₁₈ silica gel minicolumn and subsequent measurement of the absorbance of N2N at λ = 508 nm after its elution. The applicable concentration range, the detection and the relative standard were the following: for P4R, from 0.30 to 20.0 mg/L; 0.052 mg/L 1.1%; and for N2N, between 0.020 to 3.0 mg/L 0.003 mg/L and 1.1%. The method was applied to the determination of small amounts of N2N present in P4R in food and cosmetic products. Percentages of recovery between 95 and 105% were obtained in all instances. The method was applied satisfactorily to the determination of the compounds P4R and N2N in samples of sweets and cosmetic products when compared to results offered by a HPLC reference method. Received April 5, 2001. Revision July 25, 2001.     

顶空进样GC-SIM-MS测定硝唑尼特中溶剂残留甲醇含量

利用气相色谱-选择离子监测质谱联用仪(GC-SIM-MS)测定硝唑尼特样品中溶剂残留甲醇的含量,顶空进样,温度为70℃,时间为20 min.SIM定量离子m/z 32,参考离子m/z 31,30和29.甲醇质量浓度在0.5~100μg/m L内呈良好的线性(R~2=0.999 92).方法相对标准偏差为2.49%~4.85%,样品加标回收在94.5%~102.8%之间,检测限为0.5μg/m L,符合定量分析的要求.     

Liquid chromatographic determination of penicillins by postcolumn degradation with sodium hypochlorite using an hollow-fibre membrane reactor

A sensitive, high-performance liquid chromatographic method involving postcolumn degradation with sodium hypochlorite and using a hollow-fibre membrane as a reactor is described for the determination of penicillins. Penicillins were separated on a C18 column followed by postcolumn reaction with sodium hypochlorite and sodium hydroxide using aminated and sulphonated hollow-fibre membrane reactors immersed in each solution, and detected at 270-280 nm based on the UV absorbances of the degradation products. At penicillin concentrations of 2 micrograms/ml, the precisions (relative standard deviation) were 2.28-4.78%. The detection limits of the proposed method were 2.5-25 ng for each penicillin at a signal-to-noise ratio of 3. Ampicillin and its metabolites [(5R,6R)-ampicilloic acid, the (5S,6R)-epimer and (2R)-pierazine-2',5'-dione] in human serum and urine were simultaneously determined by this method.