以石墨烯基电极为工作电极,研究了呋喃西林(NF)和氨基脲(SEM)的伏安检测方法。循环伏安(CV)扫速0.10 V/s时,在醋酸-醋酸钠缓冲溶液(pH 6.0)中NF发生不可逆氧化还原,过程受吸附控制。缓冲溶液种类、pH值、富集时间等优化情况下,NF的还原峰电流(ipc)与其浓度在20.0-80.0 nmol/L范围内呈线性关系,检测限为12.0 nmol/L(S/N=3)。CV扫速为0.10 V/s时,在pH4.1的醋酸-醋酸钠缓冲溶液中SEM也发生吸附控制的不可逆氧化还原。优化条件下,SEM的氧化峰电流(ipa)与其浓度在1.3-39.9μmol/L范围内呈线性关系,检测限为0.2μmol/L。优化条件下,NF和SEM可以顺序测定,检测限分别为71.0 nmol/L和0.3μmol/L,平均回收率分别为87%和90%。应用于测定淡水渔业水样中二者残留量,得到了较满意的结果。
Voltammetric method for determining nitrofurazone and its metabolite semicarbazide was developed by employing grapheme-based electrode as working electrode.When the scan rate was 0.10 V/s,an irreversible adsorption-controlled redox reaction of nitrofurazone occurred in the NaAcHAc buffer of pH 6.0.Under the conditions of optimized parameters,including buffer solution,pH,accumulation time,etc,the dependence of the ipc on the concentration of nitrofurazone in the range of 20.0-800.0 nmol/L was linear with a detection limit of 12.0 nmoL/L (S/N =3).At the same scan rate,semicarbazide also had an irreversible adsorption-controlled redox reaction in the NaAc-HAc buffer of pH 4.1.Under optimized conditions,linear relationship between ipa and the concentration of semicarbazide was obtained in the range of 1.3-39.9 μ mol/L with a detection limit of O.2 μmol/L.Under the other set of optimized parameters,nitrofurazone and semicarbazide could be detected in the same buffer solution subsequently,with the detection limit of 71.0 nmol/L and 0.3 μmol/L,respectively,and the average recovery was found to be 87% and 83%,respectively.The concentrations of the two molecules in real fishery water samples were successfully determined using this method.