Comparative evaluation of HPLC method and acetyl acetone method in determination of formaldehyde in Fish

The fish and shellfish are the highly perishable food commodity. Formaldehyde is used by fishermen and fish vendors to preserve the freshness and quality of fish and seafood. The present study was conducted to compare the reliability of the quantitative methods for determination of formaldehyde content in fish. The methods selected were colorimetric analysis by using Nash reagent in UV-Vis spectrophotometer and chromatographic detection using Dinitrophenyl hydrazine in High performance liquid chromatography(HPLC). The results showed that both the methods were highly specific without any interference from the reagent blank and fish matrix in formaldehyde determination. The standard curve of formaldehyde by the HPLC method was linear in the range of 0 - 0.1µg/ml (R2 =0.9995). The Limit of Detection (LOD) and Limit of quantification (LOQ) for matrix free calibration were 0.0004 µg/ml and 0.0012 µg/ml and for fish were 0.020 µg/g and 0.060 µg/g respectively. Accuracy was 92.63 ±4.60% and repeatability with Relative standard deviation (RSD %) were ranging from 1.77% to 4.29%. The linear range of formaldehyde by the spectrophotometric method was 0-50 µg/ml (R2=0.9988), and the LOD and LOQ for matrix free calibration were 0.55µg/ml and 1.6µg/ml whereas for fish were 27.5 µg/g and 80 µ/g respectively Accuracy was 83.67± 5.60% and repeatability with Relative standard deviation(RSD %) were ranging from 2.66% to 6.89%.Both HPLC and UV detection methods can be used for quantitative analysis of formaldehyde in fish, and the major advantages of HPLC are that it is quick, simple and sensitive.