【作者】 刘卫国；

【导师】 张新申；

【作者基本信息】 四川大学 ， 皮革化学与工程， 2002， 硕士

【摘要】 含铬化合物由于其优越的性能，在冶金、颜料、制革以及木材防。腐等行业得到广泛的应用，已形成一个重要的工业门类。铬在自然界中主要以+3和+6价的化合物存在。Cr（Ⅲ）是人体必须的微量元素，而Cr（Ⅵ）则是公认的致癌物质，对人体和其他生物体都存在巨大的危害作用。为此世界各国对环境和皮革等工业制品中Cr（Ⅵ）含量都制定有严格的控制标准。可用于测定Cr（Ⅵ）的仪器分析方法有很多，包括分光光度法、原子光谱法、极谱法、流动注射分析法、电化学法、化学发光法等，这些分析方法各有优缺点。 本文通过改进传统的流动注射分析流路， 提出了自动参比流动注射分光光度法测定Cr（Ⅵ）的分析方法。并将此方法应用于皮革中Cr（Ⅵ）含量的测定。 首先对可用于Cr（Ⅵ）测定的流动注射分析流路进行了比较，确定了自动参比流动注射分光光度法分析的分析流路。通过实验确定利用分析条件为：显色剂中DPC浓度0.5mmol／L，硫酸浓度0.4mol／；反应液流速2.5ml／min，反应盘管长度3m，进样量235.5μl。在此分析条件下，方法的检测限为0.46×10^-6g／L，在1×10^-6-1580×10^-6g／L的范围内呈良好的线性关系。 探讨了将此方法应用于皮革分析的条件，选择皮革中Cr（Ⅵ）的提取条件为：提取液为pH8.0的Na₂HPO₄缓冲溶液，在25℃下震荡提取3h，提取过程中使用氮气保护等隔绝空气的措施防止Cr（Ⅲ）的氧化。通过比较确定使用DJ-4吸附树脂对提取液进行处理。—— 实验结果显示自动参比流动注射分光光度法测定Cr（VI）具有分选择性强、灵敏度高、抗干扰能力强、速度快、重现性好、耗用试剂少、操作简单、自动化程度高的优点。实际应用实验表明，此方法不仅适用于环境水质、皮革纺织品等方面的Cr（VI）含量分析，而且由于使用了流动注射分析技术，经适当改进可进行环境水质的自动在线分析。更多还原

【Abstract】 For its excellent properties, the chemicals contain chromium have been widely used in many fields. In nature, chromium commonly exists in two oxidation states: chromium(III) and chromium(VI). Chromium(III) has long been recognized as an essential element for life. However, chromium(VI) is highly carcinogenic and has sever damage to human and other lives. There are numerous regulations on permissible limits of chromium(VI) in water and wastewater and industry products. Spectrophotometry, atomic absorption spectrometry and other analytical methods are applied in determination of chromium(VI).In this paper, a new method, Automatic Reference reverse Flow Colorimetry was introduced. And the application in leather analysis was also advanced.Firstly, three flow injection systems were compared and the Automatic Reference reverse Flow injection system was recognized the most fit for analysis of chromium(VI). Through tests, the conditions for analysis of chromium(VI) was chose : 0.5 mmol/L 1,5-diphenylcarbazide dissolved in 0.4 mol/L H2SO4, the flow rate of reaction solution was 2.5 ml/min, the length of reactor was 3m, and the volume of sample injection valve was 235.5ul. The method was also evaluated under this condition. The calibration graph was linear in the range of 1 x10-6-1580x 10-6g/L and the detection limit was 0.46x10-6g/L .The conditions of applying the Automatic Reference reverse Flow>Colorimetry in leather analysis was also discussed. Leather sample was extracted in 0.1 mol/L Na2HPO4 solution (pH8.0) for 3h with temperature of 25C , to avoid the oxidation of chromium(III), protection with nitrogen was suggested. The extracted samples was then bleached by flowing through DJ-4 resin.With its high sensitive, resistance to interference, easy to operate and other excellence, the Automatic Reference reverse Flow Colorimetry could be used for determination of chromium(VI) in water, wastewater, leather and other samples.更多还原