Microwave-assisted on-line derivatization for sensitive flow injection fluorometric determination of formaldehyde in some foods.
A rapid and sensitive flow injection fluorometry has been developed for the determination of formaldehyde based on the microwave on-line accelerating its Hantzsch reaction with cyclohexane-1,3-dione. Under the optimized conditions, the fluorescent intensity is proportional to formaldehyde content in the range from 0.05 ng/mL to 2.000 microg/mL. The detection limit (S/N=3) is 0.02 ng/mL and the analytical frequency is 28 injections per hour. The relative standard deviations are 2.2% and 3.1% for eleven injections of 0.100 and 0.001 microg/mL of formaldehyde, respectively. With the assistance of microwave irradiation, a best sensitive fluorometry was established for the determination of formaldehyde at a high analytical frequency. This method was successfully applied to food analysis without requiring any sample pretreatment, and the determination results were correlated well with those obtained by the standard method with a sample pretreatment of steam distillation.
Key Lab of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Material Science, Shaanxi Normal University, 199 South Chang'an Road, Xi'an, Shaanxi 710062, China.
Xiao-Qing
XQ
Zhao
Zhi-Qi
ZQ
Zhang
D003512:Cyclohexanones / Q000737:chemistry; D017022:Flow Injection Analysis; D005504:Food Analysis / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D005557:Formaldehyde / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D008872:Microwaves; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence / Q000379:methods*
D003512:Cyclohexanones; D005557:Formaldehyde; C004636:1,3-cyclohexanedione