十二烷基磺酸钠存在下DBC-偶氮氯膦分光光度法测定化学试剂中的痕量铝

Spectrophotometric Determination of Aluminium in Chemical Reagents with DBC-chlorophosphonazo in the Presence of Sodium Dodecyl Sulfonate

研究在pH 4.3 HAc-NaAc缓冲介质中,Al （Ⅲ）-（DBC-偶氮氯膦）-十二烷基磺酸钠（SDS）体系光度性质.研究结果表明：该显色体系的λmax=622 nm,ε622 nm=1.41×10^4 L·mo^l-1·cm^-1,络合物组成比为Al（Ⅲ）：（DBC-CPA）=1：1, 铝量在0.20～1.20 mg·L^-1范围内遵守比耳定律.方法已满意地用于碳酸氢钠、氢氧化钠中痕量铝的测定.

In an acetic acid-sodium acetate buffer solution of pH 4.3, aluminium（ Ⅲ ）reacts with DBC-chlorophosphonazo （DBC-CPA） in the presence of sodium dodecyl sulfonate（SDS） to form a violet-blue complex. The composition of the complex is Al（ Ⅲ ） ： （DBC-CPA） = 1 ： 1. The maximum absorption of the complex exhibits that λmax is 622 nm and the molar absorptivity is 1.41 × 10^4 L·mol^-1· cm^-1 Beer law is obeyed over the range of 0.20 - 1.20 mg· L^- 1 for aluminium. The method was satisfactorily used in the determination of trace amounts of aluminium in sodium hydrogen carbonate and sodium hydroxide.