论文部分内容阅读
5-Br-DEPAP分光光度法测定钒,由于在低酸度显色,选择性欠佳。而5-Br-DEPAP-H_2O_2—钒三元络合物能在较高酸度下形成,络合物吸收峰在595nm处;随着显色酸度提高,Fe(Ⅲ)、Ca(Ⅱ)、Co(Ⅱ)、Ti(Ⅳ)的干扰减少,而钒的三元络合物吸光度下降较缓,当酸度为0.72N硫酸时,仅0.2毫克的钛(以TiO_2计)有较小干扰,提高了方法的选择性,在一般测钒操作中,大部分采用碱熔矿,水浸取后取上层清液显色,则钛的干扰亦可消除;此时,方法的灵敏度较高(“_(595nm=4.6×10~4);10毫升显色液中,0～20微克
The 5-Br-DEPAP spectrophotometric method for the determination of vanadium shows poor selectivity due to its low acidity. The ternary complex of 5-Br-DEPAP-H 2 O 2-vanadium can be formed at higher acidity with the absorption peak of the complex at 595 nm. With the increase of chromogenic acidity, the Fe (Ⅲ), Ca (Ⅱ) (Ⅱ) and Ti (Ⅳ) decreased, while the absorbance of ternary complex of vanadium decreased slowly. When the acidity was 0.72 N sulfuric acid, only 0.2 mg titanium (with TiO 2) had less interference and increased The selectivity of the method, most of the vanadium mining operation, alkali melting, water after taking the supernatant color, the interference of titanium can also be eliminated; at this time, the method of high sensitivity ("_ ( 595nm = 4.6 × 10 ~ 4); 10ml color reagent, 0 ~ 20μg