Development and Validation of an HPLC Method for the Analysis of Chlorpropham and 3-Chloroaniline in Potato Extracts

Abstract

Chlorpropham (CIPC) is the main sprout inhibitor used by potato industry. There is concern about the residues of CIPC and its degradation product 3-chloroaniline, 3-CA; hence, analytical methods are required to analyse their residues in potato samples. An HPLC-UV method was developed and validated for the separation and quantification of these compounds using propham (IPC) as an internal standard. The chromatographic conditions required to achieve good separation were 60% mobile phase of methanol, 15-minute run time at a flow rate of 1.5 mL/min, and a detection wavelength of 210 nm using Phenomenex (ODS-2 250 mm × 4.60 mm 5 µm Sphereclone) column at an ambient temperature. The method was validated for precision, linearity, the limit of detection (LOD) and the limit of quantification (LOQ), producing high precision through RSD ≤ 0.03%, and acceptable criteria of the coefficient of determination (R2) of the calibration curves (0.990). LOD values of CIPC and 3-CA were approximately 0.01 µg/mL whereas the LOQ values were approximately 0.04 µg/mL using repeated injection approach. The proposed HPLC method was compared with the standard GC method of the CIPC residues extracted showing good agreement R2=0.99. Despite using the same extract, the recovery results for the proposed HPLC method were 13% higher than GC analysis.