【作者】 王昊云；

【导师】 钱沙华；

【作者基本信息】 武汉大学 ， 环境科学， 2004， 硕士

【摘要】 环境中痕量元素的分析方法是环境分析化学的研究内容之一。本文研究了水样中痕量金、铋、砷的分析方法,具体研究内容如下: 1.研究了交联壳聚糖(CCTS)预富集分离火焰原子吸收法(FAAS)测定水样中痕量金的条件。提出了用CCTS作为富集剂,预富集、分离水样中的痕量Au(Ⅲ)的新方法。研究结果表明:在pH=4.00、吸附时间为25分钟的条件下,CCTS对金的吸附率可达99.0%,采用硫脲可将吸附到CCTS上的金定量洗脱。将CCTS用于水中痕量金的预富集,富集倍数可达20倍。用火焰原子吸收光谱法检测,检出限(3б,n=6)为0.088μg/ml,相对标准偏差(RSD)小于5.86%,回收率在89.5-95.8%之间。 2.研究了纳米二氧化钛作为富集剂,火焰原子吸收法测定水样中痕量铋的条件。研究结果表明:pH在2.00—9.00的范围内、吸附时间为15分钟的条件下,纳米二氧化钛对Bi(Ⅲ)的吸附率可达100%,采用HCl(5M)可将吸附到纳米二氧化钛上的Bi(Ⅲ)定量洗脱,测定出纳米二氧化钛对Bi(Ⅲ)的饱和吸附量为613mg/g。将纳米二氧化钛用于水样分析,富集倍数可达30倍,检出限(3б,n=6)为0.030μg/ml,相对标准偏差(RSD)小于3.03%,回收率在86.4-94.7%之间。 3.研究了CCTS预富集,二乙基二硫代氨基甲酸银分光光度法(Ag-DDTC)测定环境标准样品和水样中痕量As的条件,提出了一种新的总砷分析方法。研究结果表明:在pH=3.00、吸附时间为90分钟的条件下,CCTS对As(Ⅴ)的吸附率可达97.8%,而对As(Ⅲ)的吸附率只有31%。在pH=3.00、吸附时间为80分钟的条件下,加入0.1ml的吡咯啶二硫代氨基甲酸铵--APDC(0.5%,w/v),CCTS对As(Ⅲ)的吸附率可达94.5%,对As(Ⅴ)的吸附率可达100%。用该法测定东湖水样中的As的含量,以及牡蛎标样中的总砷,结果可靠,检出限(3б,n=6)为1.32μg/L,相对标准偏差(RSD)小于7.17%,回收率在89.3-95.4%之间。更多还原

【Abstract】 Analysis of element is an important field of environmental analytical chemistry. In this thesis, trace element Au, Bi and the total amount of As in aqueous solution are researched.1. A new method is proposed for using CCTS in preconcentration and removal of Au（III） in water sample, and the adsorption behavior of Au（III） was studied. The adsorption rate by CCTS was 99.0% at pH4. 0, and Thiourea（2. 5% W/V） can completely elute the Au（III） on CCTS. The enriching time is about 20 min. Using flame atomic absorption spectrometry（FAAS） determination, the detection limit （3σ, n=6） was 0.088μg/ml, and the relative standard deviation（RSD） at concentration level of 10μg/ml was less than 5.86%. This preconcentration method is simple, quick and has good anti-disturbance ability.2. A new method is proposed for the using of nanometer-size TiO₂ proconcentrating and removal of Bi（III） in water sample, and the adsorption behavior of Bi（III） was also studied. The adsorption rate by nanometer-size TiO₂ was 100% at pH2. 0-9. 0 and the adsorbing time was 15min, HC1 （5M） can completely elute Bi （III） on nanometer-size TiO₂. The enriching time is about 15 min in preconcentrating Bi （III） by nanometer-size TiO₂. Using flame atomic absorption spectrometry for determination, the detection limit（3σ, n=6） was 0. 030μg/ml, and the relative standard deviation （RSD） was less than 3. 03% and the recovery was between 86. 4-94. 7%.3. A novel method has been described for preconcentration of total arsenic in environmental standard samples and environmental water with CCTS, the adsorption rate was determinated by silver diethyldithiocarbamate spectrophotometric method.At 3.00 pH value,the adsorption rates of CCTS were 97.8% for As（V） and 31.0% for As （III）. After adding 0. lml APDC, the adsorption rates of CCTS were 100% for As （V） and 94. 5% for As （III）. So the total amount of As was obtained. The detection limit （3 6 , n=6） was 1. 32 u g/L, and the relative standard deviation（RSD） less than 7. 17% and the recovery was between 89. 3-95. 4%.更多还原