The reproducibility of the cyanide coupled derivatization and extraction method was tested in 10.0 mL of surface water.
Intra-day accuracy and precision were evaluated by five spiked samples at concentrations of 0.1, 1.0 and 5.0 mg L1 for cyanide, and inter-day accuracy and precision were determined by their recovery in spiked samples on five different days.
The accuracy was in a range of 98–102% and precisions of the assay were less than 7%, as shown in Table 2.