校正矩阵同时2单点沉淀滴定法研究

本文将校正矩阵计算法应用于单点沉淀滴定法中，同时测定了卤素及硫氰酸盐混合物各组分含量讨论了方法原理、指定电位的确定及常数矩阵的建立对２８个二元、三元及四元混合样进行分析，获得满意结果     

主成分分析同时测定多组分金属离子

将主成分分析用于同时单点pH络合滴定,可同时测定多组分金属离子。讨论了方法原理、pH值的选择,建立了主成分分析常数矩阵。对四元金属离子混合样进行了多次测定,均获得满意结果。     

光度法同时测定地质样品中的钼钨锡锑

以水杨基荧光酮为显色剂,确定了光度分析法同时测定钼、钨锡、锑四组份的最佳条件。并采用迭代目标转换因子分析光度法,对地质样品中上述四组份进行了测定,测定结果的相对误差一般小于１０％。浓度矩阵的实验设计、主因子数的确定、干扰及消除等问题进行了讨论。     

用氯离子选择电极同时分析水中Cl~－、Br~－、I~－的含量

本文研究了氯离子选择电极同时测定水中Ｃｌ￣－、Ｂｒ￣－、Ｉ￣－的方法。利用氯电极对Ｂｒ￣－、Ｉ￣－的响应，用混合加入法测定，非线性最小二乘法计算求解。测定了实际体系中Ｂｒ￣－、Ｉ￣－在氯电极上的选择系数，然后用多次标准加入法测定，迭代法同时计算各组份的分析结果，从而实现了用氯电极同时分析水中Ｃｌ￣－、Ｂｒ￣－、Ｉ￣－的含量。     

校正矩阵同时分光光度法测定人发中钙、镁、锌

将校正矩阵计算法应用于分光光度法中,同时测定了人发中的钙镁锌含量。讨论了方法原理和最佳实验条件,对４个发样和模拟样进行了测定,取得满意结果。     

分光光度法同时测定多元素的研究(Ⅱ)——以CPA-矩阵法计算混合体系中微量锆和铪

本文将m-NPF+CTMAB体系用于锆、铪混合物中微量锆、铪的同时测定。确定了同时测定锆,铪的最佳实验条件。通过使用CPA-矩阵法计算解决了混合体系中锆、铪分量的测定;对光度分析中应用CPA-矩阵法的关键——选择适宜的测定波长问题作了进一步讨论,提出了“相关波长”和“相关组份”的概念。     

利用阻尼因子矩阵法分光光度同时测定多组分体系

本文对多组份体系同时测定的CPA矩阵法进行了改进,降低了P矩阵对实验中偶然误差的敏感程度。将此法用于PAR-重金属离子体系的测定,获得了满意的结果,并用于实际样品的分析。     

化学蒸气发生-四通道原子荧光光谱法同时测定水样中的痕量砷、锑、硒和汞

应用自行设计的化学蒸气发生-四通道无色散原子荧光光谱仪,建立了同时测定水样中As、Sb、Se、Hg的新方法.在实验中优化了四元素同时化学蒸气发生条件和测定的最佳工作参数.在样品预处理阶段用HCl将Se6+还原为Se4+,然后用质量浓度5 g/L硫脲将As5+和Sb5+还原为As3+和Sb3+.在最佳条件下,方法对As、Sb、Se、Hg的检出限分别为0.05、0.03、0.05、0.01 ng/mL(3d);RSD分别为0.42%、0.74%、0.97%、1.0%(对5 ng/mL As、Sb、Se和0.5ng/mL Hg混合标准,n=7).用所建立的方法对不同类型水样中的As、Sb、Se、Hg进行了同时测定,测定结果与用标准方法测定所得结果之间无明显差异,各元素的加标回收率在93%～105%.     

以meso四-(对磺基苯)卟啉为柱后衍生剂同时测定微量镉、汞、锌的离子色谱法

提出了以TPPS_4为柱后色谱衍生试剂的同时测定微量汞、镉和锌的离子色谱分析法,研究了影响衍生反应速度的因素。在含氯化钠的pH 10.3～12的硼酸钠缓冲介质中,以PAR催化TPPS_4与待测金属离子反应,以硅质键合相阳离子交换剂为固定相、酒石酸—氯化钠为流动相,于10min左右定量分离金属离子并将镉的淋洗顺序调至锌前。用于废水、硅酸盐和大米分析,结果满意。     

分光光度法同时测定钙、镁、铁的研究

本文研究了以铬天青 S 为显色剂,用分光光度-CPA 矩阵法同时测定 Ca(Ⅱ)、Mg(Ⅱ)、Fe(Ⅲ)的最佳条件,进行了测定波长的选择,用于合成样品分析,取得满意的效果。     

主成份分析同时单点pM滴定法研究

本文将主成份分析应用于单点ＰＭ滴定法中，同时测定了多组分金属离子混合物各组分浓度。讨论了方法原理，建立了主成份常数矩阵，对２１个三元、四元混合样进行了测定，得到满意结果。     

SPE/GC-MS/SIM法同时测定水中7类27种SVOCs的方法研究

通过优选色谱柱,进一步改进色谱分离条件,优化前处理方法,建立了一种快速、高效测定水中7类27种半挥发性有机污染物(SVOCs)的GC-MS方法。该法可分析的目标物种类多、前处理速度快、萃取溶剂用量少、环境污染小、色谱运行时间短,40 min内完成分析,适用于大批量样品检测。另外,使用基质匹配标准溶液配制标准曲线,减小了基质效应,采用分段法选择离子(SIM)扫描,可获取更高灵敏度。该方法的检出限为0.000 4~0.013μg/L,回收率为70.5%~92.8%,相对标准偏差(RSD,n=6)不大于11.2%。     

Influence of pH and Matrix Components in the Chromatographic Response of Pesticides

The pH effect of potato, apple, and soil matrices on the chromatographic response of nine pesticides was evaluated. All chromatographic analyses were performed in duplicate on a gas chromatograph with electron capture detection. The matrix effect observed in the chromatographic response of the pesticides was evaluated by comparison. We compared the chromatographic response of each pesticide in pure solvent and in organic extract obtained for the matrices. The organic extracts were obtained by solid–liquid extraction with partition at low temperature. Depending on the matrix pH, a greater or lesser amount of co-extractives can be extracted into the organic phase, which affects the matrix effect. The pH of the samples before the extraction process was modified in order to check their influence on pesticide responses. Statistical analyses involving principal component analysis and marginal means revealed that, in the potato and apple matrices, the co-extractives exerted positive effects on the chromatographic response of the analytes. At lower pH, the extraction of co-extractives from potato and apple was favored, thus increasing the matrix effect for these samples.     

Characterization of genetic variants of human serum transferrin by isoelectric focusing: comparison between conventional and immobilized pH gradients, and application to a protocol for paternity testing

The polymorphism of transferrin (Tf) is currently being studied by isoelectric focusing in carrier ampholyte-generated pH gradients, carrier ampholyte-separator pH gradients or in immobilized pH gradients. Details for obtaining reproducible results with each of the three procedures are outlined. The effectiveness of pretreatment of serum samples with ferrous/ferric salts is discussed, and incubation times optimized after spectrophotometric measurement of the monoferric Tf conversion. Most of the presently available commercial batches of carrier ampholytes do not reliably discriminate the six common TfC subtypes. Resolution of C1, C3 and C2 was achieved by adding 20 to 90 mM HEPES slab gels prepared with various carrier ampholytes. Isoelectric focusing in carrier ampholyte-separator pH gradients cannot be recommended as a standard typing procedure because the results strongly depend on the batch of carrier ampholytes. Tf subtype resolution was only achieved by using isoelectric focusing in immobilized pH gradients with pH slopes reliably reproducible from one experiment to another. Two major shortcomings of immobilized pH gradients are a marked tendency to protein precipitation at the application site and an interaction of proteins with the charged matrix. A protocol for Tf subtyping in immobilized pH gradients is described, based on prior desialylation of samples instead of pretreatment with iron. Sample entry into the matrix was optimized by addition of 5 mM Tris to the gels, and initially running them at low voltage. Recommendations are provided for the application of Tf typing for paternity testing.     

Quantitative determination of inorganic minor cations in sodium-, calcium-, magnesium-matrix simulated samples by capillary electrophoresis

The analysis of ammonium, alkali and alkaline-earth trace cations (0.5 ppm) in samples with a calcium, sodium or magnesium matrix (500 ppm) has been achieved using 10 mM imidazole (pH 4.5) electrolyte to which a complexing agent (15-crown-5, oxalic acid or dipicolinic acid) has been specifically added in order to decrease the electrophoretic mobility of the matrix cation and thus to allow the separation of higher mobility cations at sub-ppm concentrations. The influence of several experimental parameters (complexing agent concentration, buffer pH and temperature) have been studied in order to optimize the separation. The complexing agent concentration appears to be the main parameter governing the selectivity of the cations during the analysis of matrix samples. In optimized conditions, we have checked that the separation between minor inorganic cations is not significantly altered by an increase in the matrix cation concentration. As the concentration of the matrix cation increases, the migration times of minor cations remain unchanged even for a 1000 ppm concentration of the matrix cation. Finally, these optimized buffers allow the quantitation of minor cations down to 0.05% (w/w) for calcium- or magnesium- matrix simulated samples and 0.2% (w/w) for sodium-matrix simulated samples.     

主成分分析同时单点pH滴定法研究

本文将主成分分析用于多组分同时单点ｐＨ滴定法中,讨论了方法原理,指定ｐＨ值的选择,建立了主成分分析常数矩阵,对四组分醇酮氧化酸试样及模拟样进行了多次测定,均获得了满意结果。     

主成分-偏最小二乘动力学分光光度法同时测定农药两组分

对氨基甲酸酯杀虫剂残杀威（PRO）和异丙威（ISO）的速差动力学光度法同时测定进行了研究。残杀威和异丙威均能在碱性条件下发生水解，水解生成的酚盐，均可以与对氨基苯酚及高碘酸钾混合物发生反应生成兰色化合物，且这是一个反应速率适中的动力学反应。本实验在538nm-700nm采集多个时间点下多个波长的动力学－－吸收光谱数据，构成量测矩阵。采用主成分－偏最小二乘法（PC－PLS）对测定数据进行了解析。本文对环境水样中残杀威和异丙威的含量进行了测定。取得了较好的分析结果。从而提出了一种易于实现，准确度高的残杀威和异丙威的同时测定新方法。     

Carbon‐nanotube Modified Screen‐printed Electrode for the Simultaneous Determination of Nitrite and Uric Acid in Biological Fluids Using Batch‐injection Amperometric Detection

A portable electroanalytical system applied for rapid and simultaneous determination of uric acid (UA) and nitrite (NIT) in human biological fluids (urine, saliva and blood) is reported. The system is based on batch‐injection analysis with multiple‐pulse amperometric (BIA‐MPA) detection using screen‐printed electrodes (SPEs) modified with multi‐walled carbon nanotubes. Sample dilution in optimized electrolyte (0.1 mol L⁻¹ Britton‐Robinson buffer pH 2) followed by injection of 100 μL on the electrode surface using an electronic micropipette is performed. UA is detected at +0.45 V and both UA+NIT at +0.70 V. Linear calibration plots for UA and NIT were obtained over the range of 1–500 μmol L⁻¹ with detection limits of 0.05 and 0.06 μmol L⁻¹, respectively. For comparison, a differential‐pulse voltammetric (DPV) method was optimized, and linear calibration plots for UA and NIT were obtained over range of 1–30 μmol L⁻¹ and 1–40 μmol L⁻¹ with detection limits of 0.1 and 0.3 μmol L⁻¹, respectively. BIA‐MPA is highly precise (RSD<1.3 %), fast (160 h⁻¹) and free from sample‐matrix interferences as recovery values ranged from 77 to 121 % for spiked samples (short contact time of sample aliquot with SPE). Contrarily, recovery tests conducted using DPV did not provide adequate recovery values (>150 %), probably due to the longer contact time of the SPE with the biological samples during analysis leading to a severe interference of sample matrices.