Optimum conditions employed for iodate determination were as follows: 2.5L N,N-dimethylformamide exposed to the headspace of a 10mL acidic (HCl 0.2 mol L−1) aqueous solution stirred at 1400rpm for 7 min after addition of 1mL of KI 10−3 mol L−1 for in situ iodine generation.