论文部分内容阅读
在pH3.5的HAc-NaAc缓冲介质中,盐酸二甲双胍(MFH)与Pd(Ⅱ)形成阳离子螯合物,它能进一步与酸性染料曙红Y(EY)的阴离子反应,形成离子缔合物。三元离子缔合物的生成将引起共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)光谱显著增强,其最大散射波长分别位于292、540和327 nm。在一定范围内,三种散射信号的增强(ΔI_(RRS),ΔI_(SOS)和ΔI_(FDS))均与MFH的浓度呈线性关系。方法具有较高的灵敏度,RRS、SOS和FDS法对MFH的检出限(3σ)分别为1.7、13.2和22.7 ng·m L-1。考察了适宜的反应条件和共存物质的影响,结果表明该方法选择性良好。探讨了缔合物生成及散射增强的机理。据此,提出了简便、快速、准确且高灵敏度的测定痕量MFH的光散射新方法,并应用于片剂和尿样中MFH的测定,结果满意。
In pH 3.5 HAc-NaAc buffer medium, metformin hydrochloride (MFH) forms a cationic chelate with Pd (II) which can further react with the anion of the acid dye Eosin Y (EY) to form an ionic association. The formation of ternary ion association will result in significant enhancement of RRS, SOS and FDS spectra with the maximum scattering wavelengths of 292, 540 and 327 nm, respectively. Within a certain range, the intensities (ΔI_ (RRS), ΔI_ (SOS) and ΔI_ (FDS)) of the three kinds of scattering signals are linear with the concentration of MFH. The method has high sensitivity. The detection limits (3σ) of RHS, SOS and FDS for MFH were 1.7, 13.2 and 22.7 ng · m L-1, respectively. The suitable reaction conditions and the influence of coexisting substances were investigated. The results show that the method has good selectivity. The mechanism of the formation and scattering enhancement of association products was discussed. Accordingly, a simple, rapid, accurate and sensitive light scattering method for the determination of trace MFH was proposed and applied to the determination of MFH in tablets and urine samples with satisfactory results.