横向和纵向加热石墨炉原子吸收光谱法测定血清中铟的比较

Comparative study of transverse and longitudinal heating in graphite furnace atomic absorption spectrometry for the determination of indium concentration in serum

目的分别优化横向加热和纵向加热石墨炉原子吸收光谱法测定血清中铟的条件,比较两种方法的可靠性。方法以0.1%HNO3-0.1%Triton X-100(V/V)混合溶液为稀释液、1 g/L Pd(NO_(3))_(2)或Pd(NO_(3))_(2)-Mg(NO_(3))_(2)(1∶1)溶液为基体改进剂,对血清进行5倍稀释,直接用横向或纵向加热石墨炉原子吸收光谱法测定血清铟的浓度。结果纵向加热方式的原子化温度、灰化温度比横向加热低;纵向加热方式使用Pd(NO_(3))_(2)-Mg(NO_(3))_(2)做化学改进剂时峰型好且不毛糙,横向加热方式单独使用Pd(NO_(3))_(2)做化学改进剂效果更佳。横向加热的回收率为96.3%~109.0%,RSD为1.52%~4.56%;纵向加热的回收率为96.0%~103.1%,RSD为1.49%~3.65%。横向加热线性范围为0.156~100.000μg/L,相关系数为0.9996,检出限为0.156μg/L;纵向加热线性范围为0.596~100.000μg/L,相关系数为0.9993,检出限为0.596μg/L。纵向加热的灵敏度低于横向加热;线性范围、酸介质的影响和抗干扰能力两者经t检验,差异无统计学意义(t=0.165,P>0.05)。采用横向加热方式能获得更低的检出限。结论两种方法均适用于检测血清中铟。

Objective To optimize the conditions for the determination of serum indium by transverse and longitudinal heating in graphite furnace atomic absorption spectrometry(GFAAS),and to compare the reliability of the two methods.Methods The serum was diluted 5 times with 0.1%HNO3-0.1%Triton X-100(V/V)mixture as diluent and 1 g/L Pd(NO_(3))_(2)or Pd(NO_(3))_(2)-Mg(NO_(3))_(2)(1∶1)solution as matrix modifier.The concentration of serum indium was determined directly by transversely or longitudinally heated GFAAS.Results The atomization temperature and ashing temperature of lon⁃gitudinal heating were lower than those of transverse heating.When Pd(NO_(3))_(2)-Mg(NO_(3))_(2)was used as chemical improver in the longitudinal heating mode,the peak presented a good and unrough shape.When Pd(NO_(3))_(2)was used as the single chemical improver in the transverse heating mode,the effect was better.The recovery rate of transverse heating was 96.3%-109.0%,with RSD of 1.52%-4.56%.The recovery rate of longitudinal heating was 96.0%-103.1%,with RSD of 1.49%-3.65%.The linear range of transverse heating was 0.156-100.000μg/L,with a correlation coefficient of 0.9996,and a detection limit of 0.156μg/L.The linear range of longitudinal heating was 0.596-100.000μg/L,with a correlation coeffi⁃cient was 0.9993,and a detection limit of 0.596μg/L.The sensitivity of longitudinal heating was lower than that of trans⁃verse heating.The linear range,the influence of acid medium and anti-interference ability between the two methods had no statistically significant differences(t=0.165,P>0.05).A lower detection limit could be obtained by using transverse heating method.Conclusion Both methods are applicable to the determination of serum indium.