试验发现:原子吸收光谱法(AAS)在442.7 nm波长处测定钙时受到大于0.10 mg·L-1磷共存的干扰,使钙的测定结果偏低,而且此负偏差降低的幅度随磷浓度的增加而增大.试验还发现:当共存磷的量在0.1~6.0 mg·L-1之间时,钙测量值的负偏差幅度与磷浓度之间存在明显的相关性.应用反向传播人工神经网络(BP-ANN)及模拟退火两种计算法对上述非线性干扰效应进行了研究,并提出了在单一波长检测的条件下,钙、磷两元素的原子吸收光谱法同时测定,此法应用于循环水中钙、磷的同时测定.两元素的检测范围依次为0.08~10.0 mg·L-1及0.10~6.0 mg·L-1,测得其回收率分别为100.5%和98.0%.

It was found that when the concentration of co-existing phophorus was larger than 0.1 mg·L-1,negative deviations of results of calcium in AAS determination were obtained as measured at 422.7 nm,and the magnitude of decrease in absorbance of calcium was increased with the increase of concentration of co-existed phosphorus.It was also found that when the concentration of phosphorus co-existed was in the range from 0.1-6.0 mg·L-1,an obvious correlationship was observed with the magnitude of negative deviation of results of calcium.Algorithms of back propagation artificial neural network (BP-ANN) and simulated annealing (SA) were applied to study the non-linear relationship of the above mentioned interference effect,and a method of simultaneous AAS determination of Ca and P by measuring at a single wavelength of 422.7 nm was proposed.The proposed method was applied to determination of Ca and P in cycling water samples in the ranges of 0.08 to 10.0 mg·L-1 (for Ca) and 0.10 to 6.0 mg·L-1 (for P) and values of recovery found were in the ranges of 100.5% and 98.0% respectively.