悬浮液进样石墨炉原子吸收光谱法测定地质样品中痕量镓和铊

GFAAS Determination of Trace Gallium and Thallium in Geological Samples by Introducing the Sample as a Suspending Liquid

对固体悬浮液直接进样及石墨炉原子吸收光谱法测定Ｇａ和Ｔｌ进行了研究，拟定了以琼脂为悬浮剂，Ｎｉ（对Ｇａ）和Ｖ（对Ｔｌ）为基体改进剂，标准溶液进行校准的、灵敏、快速、准确测定Ｇａ和Ｔｌ的方法。在选定条件下，测得Ｇａ和Ｔｌ的特征量（１％吸收）分别为２．８×１０￣（－１１）ｇ和４．４×１０￣（－１１）ｇ，检出限（３σ）分别为２４ｐｇ和２８ｐｇ，相对标准偏差分别为６．３％（含Ｇａ６．４ｇ／ｇ，ｎ＝１１）和４．８％（含Ｔｌ１．０ｇ／ｇ，ｎ＝１３）。方法适用于地质样品中低至０．１ｇ／ｇＧａ和Ｔｌ的测定。

Optimum conditions for the determination trace of gallium and thallium are investigated.Itwas found that agar-agar as the suspending agent,Ni(for Ga)and V(for Tl)as matrix modifiers,and the calibration against standard solution are of practical use. The characteristic mass ofthe method is 2.8×10￣(-11)g Ga and 4.4× 10￣(-1)g T1,the detection limit(3σ)is 24pg Ga and 28pgTl,the RSD is 6.3%(n=11,for 6.4g/g Ga)and 4.8%(n=13,for 1.0g/g Tl).Theanalytical results of standard reference san1ples agree with the recommended values.