In buffer solution of NaAc-HCl,when congo red(CGR) is mixed with the solution of cetylpyridinium bromide(CPB) after anion surfactant(AS) is added,the colour of the soluotion become deeper,and the max absorbtion wavele...
详细信息
In buffer solution of NaAc-HCl,when congo red(CGR) is mixed with the solution of cetylpyridinium bromide(CPB) after anion surfactant(AS) is added,the colour of the soluotion become deeper,and the max absorbtion wavelength is at 570 *** this wavelength,the absorbence enhancement is proportional to concentration of anion surfactant(AS).Based on it,a photometry method determining for anion surfactant was *** the max absorbtion wavelength,anion surfactant(AS),namely,sodium lauryl sulfonate(SLS)and sodium dodecyl sulfate(SDS),in the 0~2.4×10-4 mol/L and 0~2.7×10-4 mol/L range obey Beer(s Law,and the apparent molar absorptivity(ε) of 1.28×104 L/(***) and 1.19×104 L/(***),the detection limit of 1.43×10-6 mol/L and 1.08×10-6 mol/L are obtained *** proposed method has good sensitivity and better anti-jamming ability and has been applied to the determination of anionic surfactant(AS) in water samples with satisfactory results.
基于铈-刚果红-牛血清白蛋白(Ce(Ⅲ)-CGR-BSA)三元离子缔合物的形成,构建了一种新的检测痕量铈的共振线性及共振非线性散射光谱(RNLS)分析法。研究发现,在pH 7.6的NH3-NH4Cl缓冲溶液中,Ce(Ⅲ)能够与刚果红、牛血清白蛋白反应生成粒径更大、疏水性更强的三元离子缔合物,致使体系的共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)强度迅速增加,其最大散射波长分别位于278、543和390nm处。通过条件试验确定以0.6 mL pH 7.6的NH3-NH4Cl缓冲溶液作为反应介质,0.025mg/mL刚果红溶液用量为1.8mL,0.1mg/mL牛血清白蛋白溶液用量为1.0mL,反应时间为5min,且大量存在的常见离子对Ce(Ⅲ)的测定不产生干扰。进一步考察发现,在各自最大散射波长处,3种散射光强度的增强(ΔIRRS,ΔISOS和ΔIFDS)与Ce(Ⅲ)在2.0~10.0μg/mL范围内有良好的线性关系,对Ce(Ⅲ)的检出限(3σ)分别为0.29(RRS)、0.91(SOS)和3.54ng/mL(FDS)。同时,还对反应机理和散射光谱增强的原因进行了探讨。方法用于实际水样中铈的测定,相对标准偏差为0.94%~1.2%,测定值与原子吸收光谱法的结果相一致,加标回收率介于96%~102%之间。
暂无评论