天然水中常量元素氯的含量与人类身体健康密切相关,快速、准确地测定水中氯含量具有重要意义。目前,实验室测定天然水中氯离子的方法为国标法GB/T 11896—1989《水质氯化物的测定基本信息硝酸银滴定法》。该方法通过硝酸银滴定法测定水...天然水中常量元素氯的含量与人类身体健康密切相关,快速、准确地测定水中氯含量具有重要意义。目前,实验室测定天然水中氯离子的方法为国标法GB/T 11896—1989《水质氯化物的测定基本信息硝酸银滴定法》。该方法通过硝酸银滴定法测定水中氯离子。由于硝酸银滴定法依靠指示剂颜色的变化来判断滴定终点,容易造成较大检测误差。因此,为了快速、准确地测定天然水中氯离子含量,本文建立了离子选择电极法。该方法首先配制100 mg/L的氯化钠(NaCl)标准溶液,然后分别取0.5 m L、2.5 mL、5.0 m L标准溶液用以绘制标准曲线,实现天然水中氯离子的定量检测。该方法对天然水中氯离子的检测限为5.2 mg/L,测得氯离子标准溶液回收率为91.7%～101%,相对标准偏差范围为4.5%～6.4%。该方法可以准确测定天然水中的氯离子含量,且较国标法具有定量准确、操作简单、快速等优点,并且可以满足天然水中氯离子含量的测定。展开更多
To study arsenic （As） content and distribution patterns as well as the genesis of different kinds of water,especially the different sources of drinking water in Guanzhong Basin,Shaanxi province,China,139 water sampl...To study arsenic （As） content and distribution patterns as well as the genesis of different kinds of water,especially the different sources of drinking water in Guanzhong Basin,Shaanxi province,China,139 water samples were collected at 62 sampling points from wells of different depths,from hot springs,and rivers.The As content of these samples was measured by the intermittent flowhydride generation atomic fluorescence spectrometry method （HG-AFS）.The As concentrations in the drinking water in Guanzhong Basin vary greatly （0.00-68.08 tg/L）,and the As concentration of groundwater in southern Guanzhong Basin is different from that in the northern Guanzhong Basin.Even within the same location in southern Guanzhong Basin,the As concentrations at different depths vary greatly.As concentration of groundwater from the shallow wells （〈50 m deep,0.56-3.87 μg/L） is much lower than from deep wells （110-360 m deep,19.34-62.91 μg/L）,whereas As concentration in water of any depth in northern Guanzhong Basin is 〈10 μg/L.Southern Guanzhong Basin is a newly discovered high-As groundwater area in China.The high-As groundwater is mainly distributed in areas between the Qinling Mountains and Weihe River; it has only been found at depths ranging from 110 to 360 m in confined aquifers,which store water in the Lishi and Wucheng Loess （Lower and Middle Pleistocene） in the southern Guanzhong Basin.As concentration of hot spring water is 6.47-11.94 μg/L; that of geothermal water between 1000 and 1500 m deep is 43.68-68.08 μg/L.The high-As well water at depths from 110 to 360 m in southern Guanzhong Basin has a very low fluorine （F） value,which is generally 〈0.10 mg/L.Otherwise,the hot springs of Lintong and Tangyu and the geothermal water in southern Guanzhong Basin have very high F values （8.07-14.96 mg/L）.The results indicate that high As groundwater in depths from 110 to 360 m is unlikely to have a direct relationship with the geothermal water in the same area.As concentration of all reservoirs and rivers （both contaminated and uncontaminated） in the Guanzhong Basin is 〈10 μg/L.This shows that pollution in the surface water is not the source of the high-As in the southern Guanzhong Basin.The partition boundaries of the high-and low-As groundwater area corresponds to the partition boundaries of the tectonic units in the Guanzhong Basin.This probably indicates that the high-As groundwater areas can be correlated to their geological underpinning and structural framework.In southern Guanzhong Basin,the main sources of drinking water for villages and small towns today are wells between 110-360 m deep.All of their As contents exceed the limit of the Chinese National Standard and the International Standard （〉10 μg/L） and so local residents should use other sources of clean water that are 〈50 m deep,instead of deep groundwater （110 to 360 m） for their drinking water supply.展开更多
文摘天然水中常量元素氯的含量与人类身体健康密切相关,快速、准确地测定水中氯含量具有重要意义。目前,实验室测定天然水中氯离子的方法为国标法GB/T 11896—1989《水质氯化物的测定基本信息硝酸银滴定法》。该方法通过硝酸银滴定法测定水中氯离子。由于硝酸银滴定法依靠指示剂颜色的变化来判断滴定终点,容易造成较大检测误差。因此,为了快速、准确地测定天然水中氯离子含量,本文建立了离子选择电极法。该方法首先配制100 mg/L的氯化钠(NaCl)标准溶液,然后分别取0.5 m L、2.5 mL、5.0 m L标准溶液用以绘制标准曲线,实现天然水中氯离子的定量检测。该方法对天然水中氯离子的检测限为5.2 mg/L,测得氯离子标准溶液回收率为91.7%～101%,相对标准偏差范围为4.5%～6.4%。该方法可以准确测定天然水中的氯离子含量,且较国标法具有定量准确、操作简单、快速等优点,并且可以满足天然水中氯离子含量的测定。
基金supported financially by the Chinese National Science Foundation Project (41172310, 40171006)the Major State Basic Research Development Program (973) (2014CB238906)the National High Technology Research and Development Program (863) ofChina (2004AA601080, 2006AA06Z380)
文摘To study arsenic （As） content and distribution patterns as well as the genesis of different kinds of water,especially the different sources of drinking water in Guanzhong Basin,Shaanxi province,China,139 water samples were collected at 62 sampling points from wells of different depths,from hot springs,and rivers.The As content of these samples was measured by the intermittent flowhydride generation atomic fluorescence spectrometry method （HG-AFS）.The As concentrations in the drinking water in Guanzhong Basin vary greatly （0.00-68.08 tg/L）,and the As concentration of groundwater in southern Guanzhong Basin is different from that in the northern Guanzhong Basin.Even within the same location in southern Guanzhong Basin,the As concentrations at different depths vary greatly.As concentration of groundwater from the shallow wells （〈50 m deep,0.56-3.87 μg/L） is much lower than from deep wells （110-360 m deep,19.34-62.91 μg/L）,whereas As concentration in water of any depth in northern Guanzhong Basin is 〈10 μg/L.Southern Guanzhong Basin is a newly discovered high-As groundwater area in China.The high-As groundwater is mainly distributed in areas between the Qinling Mountains and Weihe River; it has only been found at depths ranging from 110 to 360 m in confined aquifers,which store water in the Lishi and Wucheng Loess （Lower and Middle Pleistocene） in the southern Guanzhong Basin.As concentration of hot spring water is 6.47-11.94 μg/L; that of geothermal water between 1000 and 1500 m deep is 43.68-68.08 μg/L.The high-As well water at depths from 110 to 360 m in southern Guanzhong Basin has a very low fluorine （F） value,which is generally 〈0.10 mg/L.Otherwise,the hot springs of Lintong and Tangyu and the geothermal water in southern Guanzhong Basin have very high F values （8.07-14.96 mg/L）.The results indicate that high As groundwater in depths from 110 to 360 m is unlikely to have a direct relationship with the geothermal water in the same area.As concentration of all reservoirs and rivers （both contaminated and uncontaminated） in the Guanzhong Basin is 〈10 μg/L.This shows that pollution in the surface water is not the source of the high-As in the southern Guanzhong Basin.The partition boundaries of the high-and low-As groundwater area corresponds to the partition boundaries of the tectonic units in the Guanzhong Basin.This probably indicates that the high-As groundwater areas can be correlated to their geological underpinning and structural framework.In southern Guanzhong Basin,the main sources of drinking water for villages and small towns today are wells between 110-360 m deep.All of their As contents exceed the limit of the Chinese National Standard and the International Standard （〉10 μg/L） and so local residents should use other sources of clean water that are 〈50 m deep,instead of deep groundwater （110 to 360 m） for their drinking water supply.
