2.4. Calibration and quantization
The calibration curve for the linearity test was established by adding 14.0, 20.0,100, and 200 mL of cyanide standard (0.05 mg L1 in 0.2% NaOH solution), 10.0, 20.0 mL of cyanide standard(5.0 mgL1 in 0.2% NaOH solution) and 20 mL of 2.5 mg L1 C13N15 as an internal standard in 10.0 mL of surface water, in which the analyte was not detected.