β修正酸性铬蓝K光度法测定痕量钙

β-Corrction Spectrophotometric Determination of Calcium with Acid Chrome Blue K

在碱性溶液中，钙（Ⅱ）与酸性铬蓝Ｋ反应，生成红色配合物．本文用此显色反应以β修正光度法测定痕量钙，该法能消除反应液中过量酸性铬蓝Ｋ的干扰，修正吸光度Ａβ与钙浓度ｘ呈良好线性关系，提高了分析灵敏度、准确度和精密度．钙在０—２．０ｍｇ·Ｌ－１浓度范围，遵守Ｂｅｅｒ定律，对水样和苹果分中Ｃａ的析表明，ＲＳＤ≤５．１％，标准加入回收率８９．７－１０８％．钙检出限０．０３ｍｇ·Ｌ－１。

In basic solution calcium may recact with acid chrome blue K(ACBK) to change sucha colorecd solution from blue to red.β-correction spectrophotometric method was studied for the determination of calcium in water and foods.The method can eliminate the effect of excess ACBK to make the linear relation of β-corrected absorbance with the concentration of calcium.All of the sensitivity,precision and accuracy are found to be incereased.Results have shown that the detection limit for calcium is 0.03 mg/L and the recovery was found to be between 89.7 and 108 % and the relative standard deviation was less than 5.1%.