毛细电泳法测定水中的铵和10种金属离子

Determination of Ammonium and 10 Metal Ions in Water by Capillary Electrophoresis

水体铵和重金属离子的污染加剧,其准确快速测定非常重要。采用高压毛细电泳方法,进行水中铵测定的干扰因素实验,并利用F检验和t检验进行了测定水中铵的毛细电泳法和纳氏比色法之间的显著性检验,并且进行了测定Mg^(2+)、Ca^(2+)的毛细电泳法和滴定法之间的显著性检验。结果发现:采用15mmol/L咪唑+2mmol/L乙醇酸的水溶液为流动相,在2mmol/L 18-冠-6醚存在下,K^+、Na^+、Mg^(2+)、Ca^(2+)、Li^+、Cr^(3+)、Cd^(2+)、Zn^(2+)、Cu^(2+)、Fe^(3+)、Ni ^(2+)、Pb^(2+)和Hg^(2+)对水中NH_4^+的测定不干扰;K^+、Na^+、Mg^(2+)、Ca^(2+)、Li^+、Cr^(3+)、Cd^(2+)、Zn^(2+)、Cu^(2+)、Fe^(3+)、Ni ^(2+)、Pb^(2+)和Hg^(2+)实现了相互分离。进而得到测定水中NH_4^+工作曲线为:y=-3.567x+22.53(R2=0.999),线性区间为:0.2~175.0mg/L,定性检测限为0.05mg/L,回收率为101.2%,相对标准偏差RSD为0.21%。测定10种金属离子的回收率为97%~101%,检测限为0.01~0.10mg/L,相对标准偏差RSD为0.2%~3.1%。经计算发现毛细电泳法与纳氏比色法测定水中NH_4^+无显著性差异,测定Mg^(2+)、Ca^(2+)的毛细电泳法和滴定法之间无显著性差异。建立了同时测定水中铵和10种金属离子的毛细电泳法,该法干扰少、操作简单、重现性好、灵敏度较高、准确度较高而且线性较宽。

The pollution of ammonia and heavy metal becomes more and more serious.So the fast determination of ammonium and heavy metal is very important.High-pressure capillary electrophoresis was used for interference factors experiment in ammonia determination.Besides,the significance test between the capillary electrophoresis method and Nessler＇s colorimetric method in determination of ammonium was done by Ftest and t test.And the significance test between the capillary electrophoresis method and titration method in determination of Ca^（2＋）and Mg^（2＋）was done by Ftest and t test.The results show that when the water solution which consists of imidazole（15mmol/L）＋glycolic acid（2mmol/L）is used as the mobile phase under the existence of 18-crown-6（2mmol/L）,the determination of NH_4~＋is not affected by K~＋,Na~＋,Mg^（2＋）,Ca^（2＋）,Li~＋,Cr^（3＋）,Cd^（2＋）,Zn^（2＋）,Cu^（2＋）,Fe^（3＋）,Ni ^（2＋）,Pb^（2＋）,Hg^（2＋）;K~＋,Na~＋,Mg^（2＋）,Ca^（2＋）,Li~＋,Cr^（3＋）,Cd^（2＋）,Zn^（2＋）,Cu^（2＋）,Fe^（3＋）,Ni ^（2＋）,Pb^（2＋）and Hg^（2＋）are separated from each other.The working curve of NH_4~＋determination is y=-3.567x＋22.53（R2=0.999）;the linear range is0.2~175 mg/L;the qualitative detection limit is 0.05 mg/L;the recovery is 101.2%;the relative standard deviation is 0.21%.The recovery rate of 10metal irons is 97%~101%;the limit of detection is0.01~0.10mg/L;the relative standard deviation is 0.2%~3.1%.It is found that there is no significant difference between the method of Nessler＇s colorimetry and the method of capillary electrophoresis,and there is no significant difference between the capillary electrophoresis method and titration method.The capillary electrophoresis method is established to determine simultaneously the ammonium and 10 metal irons in water,which has the advantages of less interference,simple operation,good reproducibility,wide linearity,high sensitivity and high accuracy.