Acetylacetone Spectrophotometric Determination of Formaldehyde Content in Vegetables and Risk Assessment

【Objective】The study was conducted to establish a fast method for the detection of formaldehyde content in vegetables, identify the residue level and understand the dietary exposure risk of formaldehyde in vegetables.【Method】The single factor experiment was used to optimize the key experimental conditions, and then a method acetylacetone spectrophotometry for the detection of formaldehyde contents in vegetables was established. The formaldehyde contents of 383 vegetable samples were analyzed and the exposure risk of formaldehyde in vegetables was assessed with point evaluation method.【Result】The detection limit and the quantitation limit for the determination of formaldehyde in vegetables with acetylacetone spectrophotometry were 0.45 and 1.5 mg/kg, respectively; At the added levels of 1.5, 7.5 and 15 mg/kg, the recovery rates ranged from 86.33% to 92.4% with the relative standard deviations were of 2.23%-4.21%. The detection rates of formaldehyde in different vegetables were 5.00%-72.73% with the total detection rate of 26.37%, and the average detection values of different vegetables were 0.47-1.67 mg/kg. The dietary exposure levels of formaldehyde contents in different vegetables to the general population ranged from 0.0019 to 0.068 mg/kg (bw/d) with the MOS ranging from 14.1 to 289.8, and the dietary exposure levels of formaldehyde contents in vegetables to different populations were 0.0060-0.15 mg/kg (bw/d) with the MOS ranging from 10.1 to 33.3. All the evaluated values of MOS were greater than 1.【Conclusion】The method of acetylacetone spectrophotometry is simple, accurate and sensitive, which is suitable for the fast determination of formaldehyde in vegetables. The dietary intake risk of formaldehyde residues in vegetables is low and within the acceptable range.