石墨炉原子吸收标准加入校正法测定土壤中痕量镉

选用硝酸-氢氟酸-高氯酸、硝酸-盐酸-氢氟酸-高氯酸2种消解体系,建立了石墨炉原子吸收标准加入校正法测定土壤中镉的方法,能够实现对土壤镉的准确测定.以硝酸钯为基体改进剂,优化灰化温度为550℃,原子化温度为1600℃.分别取土壤标准样品GBW07452、GBW07388经微波消解或全自动消解后,定量加入到标准溶液系列中...

Determination of Trace Cadmium in Soil by Standard Addition Correction Method of Graphite Furnace Atomic Absorption Spectrometry

Nitric acid-hydrofluoric acid-perchloric acid solution and nitric acid-hydrochloric acid-hydrofluoric acid-perchloric acid solution were adopted to establish a determination method of cadmium in soil by standard addition correction method of graphite furnace atomic absorption spectrometry.It could realize the accurate determination of soil cadmium.In this experiment,palladium nitrate was used as matrix modifier.The optimized GFAAS ashing temperature was 550℃and the atomization temperature was 1600℃.The soil standard samples GBW07452 and GBW07388 were digested by microwave digestion instrument or automatic digestion instrument,and then quantitatively added in standard solution for matrix matching.The calibration curve equations of cadmium were y=0.0179x+0.0007 and y=0.0191x-0.0004,respectively,and the linear relation were good.The detection limits were 0.007mg/kg and 0.008mg/kg,respectively,which were lower than the standard detection limits of GB/T 17141-1997.The method had high precision and accuracy because the determination results of three standard soil samples with different cadmium concentrations were consistent with the standard values and the relative standard(RSD)was within 5%.So it was suitable for the determination of cadmium in batches of soil samples.