论文部分内容阅读
基于在0.015 mol/L磷酸中,碘(Ⅴ)与过量的I-反应生成I3-,I3-进一步与溴化十六烷基三甲基铵(CTMAB)反应成1∶1离子缔合物,导致共振光散射(RLS)明显增强,建立了共振光散射法测定痕量碘的新方法。试验了酸度、试剂用量、温度和时间的影响,确定了最佳测定条件。最大共振光散射峰位于469 nm,共振光散射增强量与碘(Ⅴ)含量在0.02~0.83μg/mL范围内线性关系良好,方法的检出限为0.425μg/L。大量的共存离子不影响测定,Fe3+,Pb2+,Cu2+的干扰用EDTA消除。方法用于测定磷矿中碘,结果与碘蓝分光光度法一致,相对标准偏差小于0.37%(n=5),加标回收率为99.2%~101.0%。
I3- is further reacted with cetyltrimethylammonium bromide (CTMAB) to form a 1: 1 ion association based on the reaction of iodine (V) with excess I- in 0.015 mol / L phosphoric acid, Resonance light scattering (RLS) was significantly enhanced, and a new method for the determination of trace iodine by resonance light scattering was established. The effects of acidity, reagent dosage, temperature and time were tested to determine the best determination conditions. The maximum resonance light scattering peak is located at 469 nm. The linear range of resonance light scattering is 0.02 ~ 0.83 μg / mL. The detection limit of this method is 0.425 μg / L. A large number of coexisting ions did not affect the determination, and the interferences of Fe3 +, Pb2 + and Cu2 + were eliminated with EDTA. The method was applied to the determination of iodine in phosphate rock. The result was consistent with iodine blue spectrophotometry. The relative standard deviation was less than 0.37% (n = 5). The recoveries were 99.2% ~ 101.0%.