EXTRACTION OF MALEIC HYDRAZIDE RESIDUES FROM POTATO CRISPS AND THEIR DETERMINATION USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH UV ANDATMOSPHERIC-PRESSURE CHEMICAL-IONIZATION MASS-SPECTROMETRIC DETECTION

A method was required for the determination of maleic hydrazide residu es in potato crisps. A published method for the extraction of the anal yte from onions and potatoes was evaluated and found to be inappropria te due to the inability of the extracting solvent to penetrate the oil y matrix. A method was developed to overcome this problem; the resulti ng recovery data (mean=92.9%, R.S.D.=8.3%, n=16) confirmed its efficie ncy, and was used to analyse 48 retail potato crisp samples. To confir m possible residues identified by screening with HPLC-UV, an HPLC-atmo spheric pressure chemical ionization MS method was developed. There wa s good agreement between the data obtained from the two detection tech niques (R(2)=0.978, slope=1.11).