摘要：采用传统国标二苯碳酰二肼分光光度法和AQ2+间断化学分析仪中的二苯碳酰二肼法测定水体中的751价铬，并对其测定影响因素进行分析，实验结果表明：测定751价铬的最佳pH值为7-8；国标法与AQ2+法的加酸种类略有不同；温度对水样中751价铬的含量无明显变化；国标法与AQ2+法无显著性差异，相对误差<0.81%，两种方法呈良好的线性关系。国标法与AQ2+法的检出限分别为0.0135mg/L、0.0235mg/L；加标回收率分别可达到91.2%-105.9%、92.3%-100.9%。采用AQ2+间断化学分析仪测定水体中的751价铬，操作方法简单，试剂用量经济，省时省力，分析达到自动化，同时保证数据的准确性，可用于地表水和污、废水中。4356
关键词：AQ2+；751价铬；二苯碳酰二肼法；pH
Determination of Hexavalent Chromium in water with the AQ2+ Auto Discrete Analyzers
Abstract: After using the GB Diphenylcarbazide method and AQ2+ Auto Discrete Analyzers to measure the Hexavalent Chromium in the water, this thesis analyzed the factors those influenced the measurement. The experimental results showed that: the optimum pH of Hexavalent Chromium value was 7 to 8; GB method and AQ2+ method the kind of acid content was slightly different; temperature of Hexavalent Chromium in water samples had no obvious change; there was no significant difference between GB method and AQ2+ method, the relative deviation of the GB method and the AQ2+ method were less than 0.81%, the two methods showed a good linear relationship. The detection limit of the GB method and AQ2+ method were respectively 0.0135mg/L, 0.0235mg/L; the standard recoveries was from 91.2% to 105.9% and from 92.3% to100.9%.. Determination of hexavalent chromium in water by AQ2+ in intermittent chemical analyzer, the method of operation is simple, the amount of reagent economy, time-saving, analysis to achieve automation, and ensure the accuracy of the data, and can be used for surface water and sewage, waste water.
KeyWords: AQ2＋；Hexavalent Chromium；Diphenylcarbazide；pH
目 录
1 引言 1
1.1 选题背景 1
1.2 研究意义与内容 2
2 水体中751价铬测定方法 2
2.1 常见的751价铬测定方法 2
2.1.1 二苯碳酰二肼分光光度法 2
2.1.2 火焰原子吸收分光光度法 3
2.1.3 硫酸亚铁铵滴定法 3
2.1.4 重铬酸钾法 3
2.2 常见751价铬分析仪 4
2.2.1 AQ2+间断化学分析仪 4
2.2.2 Aquakem200多元素分析仪 5
2.2.3 QC 8000型水质流动注射分析仪 5
2.2.4 CR-2000分析仪 6
2.3 AQ2+间断化学分析仪特点 6
2.3.1 AQ2+间断化学分析仪的优点 6
2.3.2 AQ2+间断化学分析仪测定751价铬的影响因素 7
3 实验部分 7
3.1 实验原理 7
3.2 实验方案的确定 8
3.3 实验装置及流程 9
3.4 样品采集 10
3.5 实验试剂及仪器 11
3.6 实验方法 11
4 实验结果与讨论 13
4.1 751价铬的标准曲线 13
4.1.1 国标法标准曲线 13
4.1.2 AQ2＋法标准曲线 13
4.2 波长对751价铬测定结果的影响 14
4.3 不同类型的酸对751价铬测定结果的影响 14
4.4 pH对751价铬测定结果的影响 15
4.5 国标法与AQ2+法的可比性 16
4.6 检出限，精密度，准确度，加标回收率 18 AQ2+间断化学分析仪测定水中Cr6+方法研究:http://www.751com.cn/huaxue/lunwen_995.html