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微量磷的测定通常采用磷钼蓝比色法,但此法的显色液稳定性较差,且灵敏度不够高;固体电极阴极溶出伏安法和极谱间接法测定磷其手续繁琐,实际应用不多;采用钼锑抗比色法可以提高测定的灵敏度和显色速度。本文采用钒(V)-钼酸铵络合吸附波极谱法测定了微量磷,获得较满意效果。试验表明,在HCl(0.2mol·L~(-1)-V(V)(9.0×10~(-5)mol·L~(-1)-钼酸铵(3.0×10~3mol·L~(-1)-丙酮(14%)体系中,磷的化合物有尖锐的络合吸附极谱波,峰电位为-0.40V(vs.SCE)。将此吸附波用于土壤和天然水样中磷的定量测定,其检测下限为5.0×10~(-8)mol·L~(-1),线性范围为6.5×10~(-8)～9.7×10~(-5)mol·L~(-1),从而建立了示波极谱法测定微量磷的新方法。本法具有准确、快速、灵敏、波形好等特点。
Phosphorolybdate blue colorimetric method is usually used for the determination of trace phosphorus. However, the color liquid of this method is poor in stability and the sensitivity is not high enough. The cathodic stripping voltammetry and polarographic indirect method for the determination of phosphorous in the solid electrode have complicated procedures, and the practical application Not much; the use of molybdenum antimony colorimetric assay can increase the sensitivity and speed of determination. In this paper, vanadium (V) - ammonium molybdate complex adsorption polarographic determination of trace phosphorus, to obtain more satisfactory results. The results showed that when the concentration of HCl (0.2 mol·L -1 -V (V) (9.0 × 10 -5 mol·L -1) -molybdate (3.0 × 10 -3 mol·L -1) (-1) -acetone (14%) system, the compound of phosphorus has a sharp complexation polarographic wave with a peak potential of -0.40 V (vs.SCE) .The adsorption wave is used in soil and natural water samples The detection limit of phosphorus was 5.0 × 10 -8 mol·L -1 and the linear range was 6.5 × 10 -8 ~ 9.7 × 10 -5 mol·L -1. (-1), a new method for the determination of trace phosphorus by oscillopolarography was established.The method has the characteristics of accurate, rapid, sensitive and good waveform.