绞股蓝中痕量铅和铜的测定──黄原酯棉分离富集火焰原子吸收光谱法

The Determination of Trace Lead and Copper in Gynostemma Pentaphylla──Flame Atomic Absorption Spectroscopy by Means of Separation and Concentration Using Cotton Cellulose Xanthate

研究了自制黄原酯棉对ＣＵ（Ⅱ）和Ｐｂ（Ⅱ）的动态吸附条件及模拟量共存元素对吸附的干扰程度，拟定了用火焰原子吸收光谱法测定绞股蓝及其浸泡液中Ｃｕ和Ｐｂ的分析方法，并对方法进行了检验。结果表明：在ｐＨ＝３、黄原酯棉用量为０．２ｇ、流速为３ｍＬ／ｍｉｎ时，浓度不低于０．０２μｇ／ｍＬ的Ｃｕ（Ⅱ）和Ｐｂ（Ⅱ）能被定量吸附；用ＨＮＯ３或１∶１ＨＮＯ３（２ｍＬ）可完全解吸；当有Ｃａ２＋、Ｍｇ２＋、Ｋ”、Ｆｅ３＋（４０ｍｇ）、Ａｌ３＋、Ｃｍ４（１０ｍｇ），Ｍｎ２＋、Ｃｒ－（５ｍｇ）和Ｎａ＋（５００ｍｇ）之一共存时未出现干扰；模拟消化液中共存离子对校正曲线影响很少；校正曲线的相关系数为０．９９７（Ｃｕ）和０．９９６（Ｐｂ）；消化法标准回收率为９６％～１０４％（Ｐｂ）和９７％～１０３％（Ｃｕ），浸出液法标准回收率为９５％～１０２％（Ｐｂ）和９７％～１０１％（Ｃｕ）。

This paper presents the following contents,the dynamic adsorptive condition of cotton cellulose xanthate (ccx) for Lead (Ⅱ) and Copper (Ⅱ ),and the degree of interference of the analogu, co-existent ions for adsorption. And drafts the analysis of the determination of lead and copper in gynostemma Pentaphylla and its soaking solution by FAAS,and gives a test to the methed. The results showl Ph2+ and Cu2+ (>0. 02μg/mL) can be adsorbed quantitatively under the following conditions,pH is 3 .the amount of CCX used is 0. 2 g,and the velocity of now is 3 mL/min,the on2+ and Ph2+ adsorbate can be eluted completely by HNO, or 1/1 HNO3(2 mL),the interference does not occur when one of the following coexistent ions as 40 mg for Ca2+,Mg2+,K+ and Fe3+, 10 mg for Al3+ and ClO4, 5 mg for Mn2+ and Cl-,and 500mg for Na+,the influence of coexistent ions in analogur digesting solution on the standard curve is slighter,the correlative coefficients of stanadard curve are 0. 997 for Cu2+ and 0. 996 for Pb2+,the standard recoveries of digesting method are 96%～104% for Pb2+ and 97%～103% for Cu2+,and of soaking method are 95 %～102% for Ph2+ and 97% 101% for Cu2+.