应用电感耦合等离子体发射光谱法同时测定柑橘中的5种稀土元素镧、铈、镨、钕和钐.对分析线选择、积分时间的选择、消解方法的选择、介质的影响等进行了试验.与干灰化法相比较,微波消解法处理样品所得结果的准确度和精密度更好.选择波长为333.749,418.660,390.844,415.608及359.260 nm 5条谱线依次作为测定镧、铈、镨、钕和钐的分析线,测得5种稀土元素的检出限(3s/k)依次为0.003 3,0.017 0,0.014 0,0.039 0及0.007 8 mg·L-1.应用此法测定了沙田柚中5种稀土元素的含量,回收率在96.8%~101.0%之间,相对标准偏差(n=5)小于5.5%.与GB/T 5009.94-2003法比较,经t检验,在置信水平a=0.05时,测定沙田柚时两种方法无显著性差异.

An ICP-AES method for the simultaneous determination of La,Ce,Pr,Nd and Sm in orange was proposed.It was found that precision of results obtained by microwave assisted sample digestion was better than those obtained by the dry ashing method.Analytical conditions,including choice of analytical sepctral lines,elimination of interferences,setting of integration time and parameters of microwave digestor,were studied experimentally.Wavelengths of 333.749,418.660,390.844,415.608 and 359.260 nm were selected as analytical lines for the determination of La,Ce,Pr,Nd and Sm respectively.Detection limits (3s/k) of La,Ce,Pr,Nd and Sm found were 0.003 3,0.017 0,0.014 0,0.039 0 and 0.007 8 mg·L-1 respectively.The proposed method was used in the determination of lanthanides in pomelo,giving values of recovery in the range of 96.8%-101.0% and values of RSD′s (n=5) less than 5.5%.Analytical results of the proposed method were compared with those of the GB method,as verified by t-test at the confidence level of a=0.05,no significant difference was found between the two methods in the analysis of pomelo.