苦胺酸偶氮变色酸光度法测定硝酸镍中痕量钴

研究了苦胺酸偶氮变色酸与钴显色反应的条件。在氨性条件下,试剂与钴发生显色反应,最大吸收波长为645nm,摩尔吸光系数为2.65×10~4L/(mol·cm),钴含量在0～ug/25mL内符合比尔定律。在以大量基体元素打底的情况下,不需另加任何其它掩蔽剂,可直接测定硝酸镍中的痕量钴。     

用冠醚和硫氰酸钾萃取光度法测定钢铁中微量铌

报道了用双(苯并-18-冠-6)和硫氰酸钾试剂萃取光度测定钢铁中的微量铌,方法的选择性好,灵敏度高,ε_(400nm)=3.85×10~4L·mol~(-1)·cm~(-1),铌在1～20μg/25ml范围内有较好的线性关系,线性回归方程A=0.936C(mg·ml~(-1))-1.425×10~(-3)。     

间羧基氯磺酚的合成及其光度法测定钢中铌

报道了间羧基氯磺酚(SCPmK)的合成及其与铌的显色反应,在1．8-3．0mol·L-1的盐酸介质中,铌与SCPmK形成1∶1的深蓝色配合物,最大吸收波长在640nm处,其摩尔吸光系数为1． 08×10５L·mol-1·cm-1(乙醇溶液),铌含量在0-60μg／50ml符合比耳定律,运用此法可直接测定钢中微量铌。     

苦氨酸偶氮变色酸光度法测定对苯二甲酸中的微量钴

研究显色剂苦氨酸偶氮变色酸与钴的显色反应.在pH 10的柠檬酸铵一氨水溶液中,钴与苦氨酸偶氮变色酸反应生成绿色配合物,最大吸收波长为650 nm,表观摩尔吸光系数为2. 7×104.钴的含量在0～50μg/(25 mL)范围内符合比耳定律.该方法用于对苯二甲酸中微量钴的直接测定,测定结果的相对标准偏差小于5%(n=5),加标回收率为98%～102%.     

间氯偶氮安替比林光度法测定钛

建立了间氯偶氦安替比林试剂测定钛的新方法。经离子交换分离后,利用Ti(Ⅳ)-H_2O_2-试剂生成的三元配合物进行光度测定。测定了两种铝合金标样,精密度和准确度令人满意。     

苦安酸偶氮变色酸褪色光度法测定硅铁中钙

在pH 11.0的氨水-NH4Cl介质中,研究了显色剂苦安酸偶氮变色酸与钙的褪色反应,建立了测定硅铁中钙的褪色光度分析方法.讨论了吸收光谱、酸度、试剂用量、干扰离子等因素的影响,确定了反应的最佳条件.在25 mL的溶液中,钙量在8～90 μg范围内符合比尔定律,该方法表观摩尔吸光系数为1.26×104 L·mol-1·cm-1,可用于硅铁中钙的测定.其RSD在1.4%～2.1%之间.     

新显色剂二溴邻羧基偶氮羧胂光度法测定海产品中微量钍

合成并研究了新显色剂二溴邻羧基偶氮羧胂(CAsA-DBC)用于光度法测定微量钍.在盐酸(1 19)介质中,钍与显色剂发生灵敏反应,生成稳定的蓝色配合物,其物质量比为nTh(Ⅳ);nCAsA-DBC=1:2,最大吸收在640 nm波长处,表观摩尔吸光率为1.11×105L·moL-1·cm-1,钍的质量浓度在20ug/25 mL以内符合比耳定律,线性回归方程A=0.093 2 C 0.000 5,相关系数为0.999 1.在试验条件下,大量常见的金属离子如钙、镁等以及与钍伴生的铀不干扰微量钍的测定.利用拟定方法对几种海产品中痕量钍作了测定,分析结果的相对标准偏差(n=5)均小于3.1%,并求得回收率在99.3%-103.5%之间.     

A Simple Sensitive Spectrophotometric Method for the Determination of Ce4+ Using Variamine Blue as a Chromogenic Reagent

A rapid and sensitive spectrophotometric method is described for the determination of trace amounts of cerium using Variamine Blue (VB) as a chromogenic reagent. The proposed method is based on the reaction of cerium with potassium iodide in acidic medium to liberate iodine, which oxidizes Variamine Blue to give a violet colored species with an absorption maximum at 560nm. Beers law was obeyed in the range 2–10µg mL^–1 of cerium. The molar absorptivity and Sandells sensitivity are found to be 1.65×10⁴L mol^–1cm^–1 and 8.48×10^–3µgcm^–2, respectively. The proposed method has been successfully applied to the determination of cerium in alloy and synthetic mixtures.     

新显色剂二溴对甲基偶氮溴磺光度法测定铈组稀土的研究及应用

研究了新显色剂二溴对甲基偶氮溴磺与铈组稀土的显色反应,在０．６ｍｏｌ．Ｌ＾－１的盐酸介质中,试剂与铈组稀土元素形成２：１稳定的蓝色络合物,其最大吸收波长位于６４２ｎｍ处,稀土含在０－１．０μｇ／ｍＬ范围内符合比耳定律。建立了直接光度法测定钢铁样品中铈组稀土总量的方法。     

新显色剂二溴对甲基偶氮溴磺光度法测定钡的研究及应用

研究新显色剂二溴对甲基偶氮溴磺光度测定微量钡的方法。在 0 .72 mol·L- 1HCl介质中 ,试剂与钡形成 2∶ 1蓝色络合物 ,其最大吸收波长位于 62 8nm,表观摩尔吸光系数为 9.9× 1 0 4 L· mol- 1· cm- 1,钡量在 0～ 2 5 μg/2 5 m L范围内符合比耳定律。方法用于钛酸钡烧结物中微量钡的测定 ,结果满意     

新试剂2-(5-硝基-2-吡啶偶氮)-5-二甲氨基苯甲酸分光光度法测定微量钴

本文报道用新试剂2-(5-硝基-2-吡啶偶氮)-5-二甲氨基苯甲酸分光光度法测定微量钴。配合物的表观摩尔吸光系数为1.31×10~5L·mol~(-1)·cm~(-1),Co∶5-NO_2-PAMB=1∶2,Co浓度在0～14μg/25mL范围内服从比耳定律。用于金属有机化合物中微量钴的测定,结果与理论值相符。     

新显色剂间碘偶氮氯膦与铋的显色反应

本较系统地研究了新显色剂２－（４－氯－２－膦酸基苯偶氮）－７－（３－碘苯偶氮）－１，８二羟基－３，６－萘二磺酸与铋的显色反应分光光度法测定铋。在硝酸和磷酸酸的混介质中，间碘偶氮氯磷与铋形成２：１的深色配合物：最大吸收波长在６８０ｎｍ，摩尔系数为１．４８×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，该方法操作简便，灵敏度高，Ｂｉ（Ⅲ）在０－１８μｇ／２５ｍＬ范围内符合比尔定律，用拟定的方法测定了可锻铸铁     

醌茜素显色分光光度法测定奋乃静

研究了奋乃静(Perphenazine,PPH)与醌茜素(Quinalizarin,QLZ)之间的荷移光谱及其性能。奋乃静作为电子给体,醌茜素作为电子受体,两者在乙醇-水介质中反应生成荷移络合物。该络合物的λmax=568nm,表观摩尔吸光系数是3.39×103 L.mol-1.cm-1,奋乃静药物质量浓度在0～35mg/L范围内服从比耳定律,相对标准偏差为1.23%(n=6),回收率为98.9%～102.4%。     

Solid Phase Extraction and Spectrophotometric Determination of Mercury in Tobacco and Tobacco Additives with p-Sulfobenzylidenerhodanine as Chromogenic Reagent

A highly sensitive, selective and rapid method for the determination of mercury based on the reaction of mercury(II) with p-sulfobenzylidenerhodanine (SBDR) and the solid phase extraction of the colored chelate with a C₁₈ cartridge has been developed. In the presence of pH 3.8 acetate buffer solution and Tween-80 medium, SBDR reacts with mercury to form a red chelate of a molar ratio of 1:2 (mercury to SBDR). This chelate was enriched by solid phase extraction with a C₁₈ cartridge and eluted from the cartridge with ethanol (containing 5% acetic acid). The enrichment factor of 50 was achieved. In the ethanol medium, the molar absorptivity of the chelate is 1.28×10⁵L·mol^–1·cm^–1 at 545nm. Beers law is obeyed in the range of 0.011.2µgmL^–1 in the measured solution. The relative standard deviation for eleven replicate samples of 0.01µgmL^–1 level is 1.52%. This method can be applied to the determination of mercury in tobacco and tobacco additives with good results.     

Determination of Molybdenum in Human Urine by Spectrophotometric Method using Thiazolylazo Compounds as Chromogenic Reagents

ABSTRACT

Four azo compounds based on diazotization of 2-aminobenzothiazole have been synthesized and characterized by elemental analysis as well as different spectroscopic techniques. The potentiality of the prepared compounds as new chromogenic reagents for the spectrophotometric determination of Mo⁶⁺ was studied by extensive investigation of optimum conditions favouring the formation of the coloured complexes. Beers law is obeyed in the concentration range 0.2-8.5 μg ml^?1 whereas Ringbom optimum concentration range was 0.8-7.5 μg ml^?1. The detection limit was 0.05 μg ml^?1. The molar absorptivity and Sandell sensitivity of the formed complexes are calculated. The effect of interfering ions on the determination of Mo⁶⁺ was investigated. The relative standard deviations for six replicate determinations of 5.0 μg ml^?1 of Mo⁶⁺ are 1.23, 1.47, 1.05 and 1.38 % using reagents I, II, III and IV, respectively. The proposed method has been applied to investigate the amount of Mo⁶⁺ in human urine samples. The molybdenum levels found between 0.5-2.1 μg/100 ml.     

Rapid Extraction Spectrophotometric Determination of Platinum Using Anisaldehyde-4-Phenyl-3-Thiosemicarbazone as a Chromogenic Reagent

Abstract

The synthesis, spectral characteristics and analytical applications of anisaldehyde-4-phenyl-3-thiosemicarbazone (APT) are described. A simple, rapid, selective and sensitive spectrophotometric method for the determination of platinum was developed based on the colour reaction between platinum (IV) and anisaldehyde-4-phenyl-3-thio-semicarbazone (APT) in the pH range 1.7 - 3.0. The yellow coloured species has an absorption maximum at 360 nm. The complexation is complete within 1 min. A five-fold excess of the reagent is required for complete complex formation. Beer's law is obeyed over the concentration range 0.1 -20 ppm of Pt(IV). The mtilar absorptivity and Sandell's sensitivity are 1.58 × 10⁴ l. mol^?1 cm^?1 and 0.0123 ug of Pt(IV) cm^?2, respectively. The effects of pH, time concentration of reagent, order of addition of reagents and the interference from various ions were investigated. The method has been employed for the determination of platinum in synthetic mixtures whose composition correspond to some alloys.