摘要
用亲脂的长链四烷基锡作中性载体制备亚硝酸根选择性电极.其选择性模式与经典的阴离子交换剂相比有显著不同,相对硝酸根的电位选择性系数改善约4个数量级.
Lipophilic long-chain tetraalkyltin compounds as neutral carriers for nitrite-sele-ctive PVC membrane electrodes show selectivity patterns radically different from thoseobtained with classical anion-exchangers.The potentiometric selectivity coefficient fornitrite ion with respect to nitrate ion has been improved by about four orders of mag-nitude.The linear response range of the electrode based on tetralauryltin(TLT)is from1×10-1mol·dm-3 down to 2×10-5mol·dm-3 with a detection limit of 5×10-6mol·dm-3.The Nernstian response of the electrode in the medium of pH≥7 gradually changes to adoubled super-Nernstian response when the solution turns slightly acidic.The change ofthe response slope has a closely relation with the stepwise complex-formation equilibr-ium of the carrier with the anion involved,which was experimentally studied by using altraviolet spectroscopy.An explanation of the anomalous response behavior as well asthe curve form of the mV-pH plot is given.
出处
《化学学报》
SCIE
CAS
1988年第11期1087-1092,共6页
Acta Chimica Sinica
基金
国家教委科学基金
