Abstract

A new simple and sensitive reverse flow injection chemiluminescence (FI-CL) method is described for the determination of formaldehyde. The method is based on the CL-emitting reaction between ninhydrin and potassium permanganate in hydrochloric acid medium, enhanced by formaldehyde (HCHO). The calibration curve is linear in the range of 0.002 to 10μg ml-1 with r = 0.9995, and the limit of detection is 4.6 x 10-4 μg ml-1. The relative standard deviation for replicate measurements is 1.5% for 4μg ml-1 of formaldehyde. The chemical and flow injection variables were studied and optimized to make the procedure suitable for determination of formaldehyde in water. It is shown that the reverse flow injection analysis could greatly improve the sensitivity and precision for determination of formaldehyde. The procedure has been applied successfully to the determination of formaldehyde in leather wastewater, and the results were statistically compared with results determined by a standard method.