PAN-S 负载纤维富集-ICP-MS 法测定畜禽饮用水中痕量铬

摘要

The Cr content in drinking water of livestock and poultry was detected by ICP-MS based on PAN-S loaded fiber [polypropylene strongly basic anion-exchange fiber treated by1-(2-pyridylazo)-2-naphthol-6-sulfonic acid (PAN-S)chelating agent ]to increase Cr sensitivity and decrease Cr detection limit in drinking water of livestock and poultry.When the volume of enrichment solution with pH 6 is less than 1 000 ml and the flow velocity of the upper column is less than 15 mL/min,Cr can be enriched effectively and Cr enrichment is not disturbed by co-existing ions of K+ ,Na+ ,Ca2+ and Mg2 .10 mL eluant of nitric acid with 0.2 mol/L can meet the measuring demand of ICP-MS method.The recovery,RSD and detection limit of the PAN-S loaded fiber with ICP-MS are 90.0% ~ 96.0%,1.0% ~ 2.2% and 0.02 μg/L respectively.The measuring results of 30 drinking water samples detected by PAN-S loaded fiber with ICP-MS and conventional spectrophotometry is the same basically,which indicates that PAN-S loaded fiber with ICP-MS can be used in Cr detection of drinking water for livestock and poultry.%为提高畜禽饮用水中痕量铬的测定灵敏度及降低检出限，采用螯合剂1-（2-吡啶偶氮）-2-萘酚-6-磺酸（PAN-S）处理聚丙烯基强碱性阴离子交换纤维，制得 PAN-S 负载纤维；用 PAN-S 负载纤维富集畜禽饮用水中痕量铬，然后用电感耦合等离子体质谱（ICP-MS）法测定，建立 PAN-S 负载纤维富集—ICP-MS 法测定畜禽饮用水中痕量铬的方法。结果表明：当待富集液体积小于1000 mL、pH 6、上柱流速小于15 mL/min时，铬可被有效富集，且富集不受 K＋、Na＋、Ca2＋、Mg2＋等共存离子的干扰；用0．2 mol/L 硝酸10 mL 能完全洗脱，洗脱液能满足 ICP-MS 法测定的要求；该方法的回收率为90．0％～96．0％，相对标准偏差（RSD）在1．0％～2．2％，检出限为0．02μg/L；应用优化的富集测定方法和常规的二苯碳酰二肼分光光度法同时对30份畜禽饮用水样品进行痕量铬的检测，两种方法的测定结果基本一致，说明优化的富集测定方法可应用于畜禽饮用水中痕量铬的检测。