Determination of iodate in waters by cuvetteless UV-vis micro-spectrophotometry after liquid-phase microextraction

作者：Pena Pereira Francisco; Senra Ferreiro Sonia; Lavilla Isela; Bendicho Carlos^*

来源：Talanta, 2010, 81(1-2): 625-629.

DOI：10.1016/j.talanta.2009.12.053

• Miniaturization
• Liquid-phase microextraction
• Microvolume UV-vis spectrophotometry
• Iodate determination
• Water analysis

The combination of liquid-phase microextraction and microvolume UV-vis spectrophotometry has been applied to the determination of iodate in natural water samples. The method is based on the reduction of iodate into vapor iodine and extraction of this volatile onto a single drop of N,N'-dimethylformamide. The following derivatization reaction was employed:
IO(3-) + 5I(-) + 6H(+) --> 3I(2) + 3H(2)O
Optimum conditions employed for iodate determination were as follows: 2.5 mu L N,N'-dimethylformamide exposed to the headspace of a 10 mL acidic (HCl 0.2 mol L(-1)) aqueous solution stirred at 1400 rpm for 7 min after addition of 1 mL of KI 10(-3) mol L(-1) for in situ iodine generation. The limit of detection was determined as 1.1 mu g L(-1). The repeatability, expressed as relative standard deviation, was 4.2% (n = 6). A large preconcentration factor (i.e. 396) was obtained in only 7 min.

• 出版日期2010-4-15