ICP-OES法测定水溶肥料中的磷和钾

P and K Elements in Water-soluble Fertilizers Determined by ICP-OES

为便捷快速地定量水溶肥料中的磷和钾,采用ICP-OES法测定水溶肥料中的磷和钾,并与传统的定量方法——重量法和火焰光度法进行比较。结果表明：在检测功率为1kW、等离子气流量为15L/min、辅助气流量为1.5 L/min、雾化气压力为200kPa、观察高度为10 mm、磷的检测波长为213.618nm、钾的检测波长为766.491nm条件下,磷和钾在0-100mg/L的线性关系R值分别为1.00和0.999,ICP对磷和钾的检出限、准确度和精密度分别为0.060 9 mg/L、0.054 6 mg/L、0.091 4 mg/L和0.043 2mg/L、0.148mg/L、0.035 0mg/L。ICP法与重量法对磷、钾的测定结果均不存在显著差异,采用火焰光度法测定水溶肥料中的钾含量偏高,且与ICP法和重量法存在显著差异。

P and K elements in water-soluble fertilizers were determined by ICP-OES and traditional quantitative methods（the gravimetric method and flame photometry method）respectively to find out the convenient and fast quantitative method for determining P and K in water-soluble fertilizers.The results showed that when P and K concentration is 0-1 000 mg/L,the R value（linear correlation）of P and K elements is 1.00 and 0.999 respectively by using ICP-OES under the conditions including 1kw of power,15L/min of plasma gas flow,1.5L/min of auxiliary flow,200 kPa of atomised barometric pressure,10 mm of observation height and 213.618 nm wavelength for P and 766.491 nm wavelength for K,and the detection limit,accuracy and precision of P and K by using ICP-OES are 0.0609mg/L,0.054 6mg/L and0.091 4 mg/L,and 0.043 2 mg/L,0.148 mg/L and 0.035 0 mg/L separately.There is no significant difference in determination of P and K content between ICP-OES and the gravimetric method but K content of water-soluble fertilizers determined by the flame photometry method is high,and there is significant difference in determination of K content between the flame photometry method and other two methods.