Single Scanning Polarographic Determination of Formaldehyde in Shrimps Enriched by Adsorption on Electrostatic Spinning Nanofibers

Electrostatic spinning nanofibers were used as carriers for SPME column which was applied to enrich formaldehyde from shrimps, and its adsorbility toward formaldehyde were studied in detail. Adsorption capacity of 5 mg·kg-1 for HCHO was found by passing 5 mg·L-1 HCHO solution through the SPME column packed with 7 mg of the nanofiber. The formaldehyde on the surface of the nanofibers was completely desorbed by extracting with acetone-H2O (17+83) mixture, and derivatized with phenylhydrazine hydrochloride. The derivate was determined by single scanning polarography. In an acetate buffer solution of pH 5.6, a sensitive reduction peak of derivate of formaldehyde was observed at the potential of -832 mV. Linear relationship between values of peak current and mass concentration of formaldehyde was obtained in the range of 2.0×10-2-2.5×10-1mg·L-1 with detection limit (3S/N) of 3.5×10-3mg·L-1. Test for recovery was made by adding standard solution to blank shrimp sample, giving values of recovery in the range of 81.6%-96.7% and RSD (n=7) ranged from 2.6% to 4.4%.