2,3,7-三羟基-9-(2,4-二羟基)苯基荧光酮荧光猝灭法测定锰(Ⅱ)

Fluorescence Quenching Method for the Determination of Manganese with 2,3,7-trihydroxy-9-(2,4-dihydroxy)phenylfluorone

在pH=9.33的NH3.H2O-NH4Cl缓冲介质中,于表面活性剂溴化十六烷基三甲铵(CTMAB)存在下,利用Mn(Ⅱ)与2,3,7-三羟基-9-(2,4-二羟基)苯基荧光酮(DHPF)形成Mn(Ⅱ)-DHPF-CTMAB三元配合物可产生荧光猝灭,建立了荧光猝灭法测定痕量Mn(Ⅱ)的新方法。该体系激发波长λex=520nm,发射波长λem=540nm,荧光猝灭值与Mn(Ⅱ)的含量在0～0.36μg/25mL范围内呈线性关系,检出限为0.02μg/25mL,在CTMAB存在下,配合物摩尔比Mn(Ⅱ)∶DHPF=1∶2。拟定方法用于测定尿样中微量锰的含量,结果满意。

In the medium of ammonia-ammonium chloride at pH=9.33 with the existence of cationic surfactant of cetyltrimethyl-ammonium bromide（CTMAB）,a new method for the determination of trace Mn2＋ was developed based on the reaction of Mn（Ⅱ）and 2,3,7-trihydroxy-9-（2,4-dihydroxy）phenylfluorone（DHPF）which resulted in the fluorescence quenching of the complex Mn-DHPF-CTMAB.The excitation and emission wavelengths are 520 nm and 540 nm,respectively.The linear range is 0~0.36 μg/25mL for determination of Mn（Ⅱ）,the detection limit is 0.02 μg/25mL,the molar-ratio between Mn（Ⅱ）and DHPF is 1∶2.The method has been applied in the determination of manganese in urine with satisfactory results.