北京市平谷区生活饮用水中11种营养元素的含量分析

Content analysis of 11 nutrient elements of drinking water in Pinggu District of Beijing City

目的了解北京市平谷区生活饮用水中营养元素锂、钠、镁、钾、钙、锰、铁、铜、锌、锶、钡的含量。方法以平谷区所有水源的水为检测对象,采用电感耦合等离子体质谱法进行检测,采用非参数检验(Mann-Whitney U检验)方法比较山区和平原地区水中11种营养元素的含量是否有差异。采用非参数检验(Wilcoxon符号等级检验)的方法比较平谷区水中锶含量与《食品安全国家标准饮用天然矿泉水》标准中规定的锶含量的下限(0.200 mg/L)是否有差异。结果平谷区饮用水中锂、镁、钙、钠、钾、铁含量的中位数分别为7.572μg/L、26.364 mg/L、7.168 mg/L、8.701 mg/L、1.355 mg/L、3.683μg/L。所有水样中铁、锰、铜、锌符合《生活饮用水卫生标准》(GB 5749—2006)的要求。锶含量的中位数为0.199 mg/L与《食品安全国家标准饮用天然矿泉水》的最低要求(0.200 mg/L)相比较,经过非参数检验(Wilcoxon符号等级检验)差异无统计学意义(P>0.05)。平原地区锶含量的中位数为0.240 mg/L,大于《食品安全国家标准饮用天然矿泉水》的最低要求(0.200 mg/L)(P<0.05)。经过非参数检验(Mann-Whitney U检验),山区水中镁、铁、锰含量高于平原地区(P<0.05);锂、钠、铜、锶的含量低于平原地区(P<0.05)。结论平谷区生活饮用水钠、镁、钾、钙、锶元素含量较丰富。长期饮用平谷区的水有利于补充人体所需的上述元素,有利于人体心血管正常活动和预防龋齿。

Objective To know the contents of nutrients lithium,sodium,potassium,calcium,manganese,iron,copper,zinc,cesium,strontium,and barium in drinking water of Pinggu District.Methods All headwaters samples of Pinggu District were tested by inductively coupled plasma mass spectrometry.Content differences of 12 nutrients in water from mountainous and plain areas were tested by non-parametric test method(Mann-Whitney U test).Nonparametric test(Wilcoxon symbol grade test)was used to compare whether there was any difference between the strontium content in the water of Pinggu District and the lower limit of strontium content(0.200 mg/L)stipulated in the National Standard of Drinking Natural Mineral Water for Food Safety.Results The median contents of lithium,magnesium,calcium,sodium,potassium,and iron in drinking water of Ping⁃gu District were 7.572μg/L,26.364 mg/L,7.168 mg/L,8.701 mg/L,1.355 mg/L,and 3.683μg/L.Iron,manganese,copper,and zinc in all water samples met the requirements of the Sanitary Standard for Drinking Water GB 5749—2006.The median content of strontium was 0.199 mg/L.There was no statistical significance between the median content of strontium and the minimum requirement(0.200 mg/L)of National Standard of Drinking Natural Mineral Water for Food Safety(P>0.05).The median content of strontium in the plain area was 0.240 mg/L,which was greater than the minimum requirement(0.200 mg/L)of National Standard of Drinking Natural Mineral Water for Food Safety(P<0.05).After non-parametric tests(Mann-Whitney U test),the contents of magnesium,iron and manganese in mountain water were higher than those in plain areas(P<0.05);the contents of lithium,sodium,copper and strontium were lower than those in plain areas(P<0.05).Conclusion The contents of sodium,magnesium,potassium,calcium and strontium of drinking water were rich in Pinggu District.Long-term drinking of water in Pinggu District is conducive to cardiovascular normal activities and preventing dental caries.