电感耦合等离子体原子发射光谱法测定云南昆阳磷矿黑色页岩中7种组分

Determination of seven components in black shale of Kunyang phosphate mine in Yunnan by inductively coupled plasma atomic emission spectrometry

黑色页岩中硅和有机质含量较高,实验采用在750℃马弗炉中灼烧除碳后,经盐酸-氢氟酸-硝酸在200℃消解处理样品,使四氟化硅逸出。选择P 213.618nm、Mg 285.213nm、Fe259.940nm、Al 396.152nm、Ca 317.933nm、Mn 257.610nm、Ti 334.941nm为分析谱线,选取耐氢氟酸进样系统,直接用电感耦合等离子体原子发射光谱法(ICP-AES)测定五氧化二磷、氧化镁、氧化铁、氧化铝、氧化钙、氧化锰、二氧化钛,从而建立了云南昆阳磷矿黑色页岩中五氧化二磷、氧化镁、氧化铁、氧化铝、氧化钙、氧化锰、二氧化钛的分析方法。在仪器最佳工作条件下,各组分校准曲线的线性相关系数均不小于0.9996;方法检出限为0.0012~0.028μg/g。方法应用于云南昆阳磷矿黑色页岩样品中五氧化二磷、氧化镁、氧化铁、氧化铝、氧化钙、氧化锰、二氧化钛的测定,结果的相对标准偏差(RSD,n=11)为0.29%~1.5%;加标回收率为97%~105%。按照实验方法测定西藏地区沉积物国家标准物质(GBW 07320、GBW 07328、GBW07331)中五氧化二磷、氧化镁、氧化铁、氧化铝、氧化钙、氧化锰、二氧化钛,测定值与认定值基本一致。

The contents of silicon and organic matters in black shale are relatively high. After burning carbon in muffle furnace at 750 ℃, the samples were digested by hydrochloric acid-hydrofluoric acid-nitric acid at 200 ℃ to release silicon tetrafluoride. P 213.618 nm, Mg 285.213 nm, Fe 259.940 nm, Al 396.152 nm, Ca 317.933 nm, Mn 257.610 nm and Ti 334.941 nm were selected as the analytical lines. The hydrofluoric acid resistant sample injection system was used for the direct determination of phosphorus pentoxide, magnesium oxide, iron oxide, aluminum oxide, calcium oxide, manganese oxide and titanium dioxide. Thus the analysis method of phosphorus pentoxide, magnesium oxide, iron oxide, aluminum oxide, calcium oxide, manganese oxide and titanium dioxide in black shale of Kunyang phosphate mine in Yunnan by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. Under the optimum working conditions of the instrument, the linear correlation coefficients of calibration curves were all greater than 0.999 6. The detection limits of the method were between 0.001 2 μg/g and 0.028 μg/g. The proposed method was applied for the determination of phosphorus pentoxide, magnesium oxide, iron oxide, aluminum oxide, calcium oxide, manganese oxide and titanium dioxide in black shale sample of Kunyang phosphate mine in Yunnan. The relative standard deviations (RSD, n =11) of the results were between 0.29% and 1.5%, and the spiked recoveries were between 97% and 105%. The contents of phosphorus pentoxide, magnesium oxide, iron oxide, aluminum oxide, calcium oxide, manganese oxide and titanium dioxide in certified reference materials of sediment in Tibet region (GBW 07320, GBW 07328 and GBW 07331) were determined according to the experimental method. The found results were basically consistent with the certified values.