乙酰丙酮衍生化高效液相色谱-荧光检测法测定食品中的甲醛

建立基于乙酰丙酮衍生化利用配有荧光检测器高效液相色谱测定食品中甲醛含量的方法。色谱柱为Eclipse XDB-C18(250 mm×4.6 mm,5μm),流动相为V(乙腈)∶V(水)=20∶80,激发波长为416 nm,发射波长为505 nm,采用外标法定量,甲醛质量浓度在0.001~20.0 mg/L范围内呈良好线性,相关系数为0.999 9。甲醛质量浓度为0.005、0.05、0.5、5.0 mg/L时相对标准偏差分别为4.2%、1.9%、1.4%和0.81%。固体及粉末样品的检出限为0.025 mg/kg,液体样品的检出限为0.025 mg/L。本方法用于干香菇、面粉及啤酒样品中甲醛含量的测定,加标回收率为92.0%~97.7%,相对标准偏差不大于5.6%。结果表明,本方法灵敏度高,方便快捷,结果可靠。

Determination of Formaldehyde in Foods by High-Performance Liquid Chromatography with Fluorescence Detection through Derivatization with Acetylacetone

A method to determine formaldehyde in foods by high-performance liquid chromatography (HPLC) with
fluorescence detection following derivatization with acetylacetone was established. The HPLC method was performed
on an Eclipse XDB-C18 (250 mm × 4.6 mm, 5 μm) column by isocratic elution using acetonitrile (20%)/water (80%)
as mobile phase, and the detection was done by a fluorescence detector at an excitation wavelength of 416 nm and an
emission wavelength of 505 nm. Formaldehyde was quantified by an external standard method. Under optimal experimental
conditions, good linearity was observed in the range of 0.001–20.0 mg/L with a correlation coefficient of 0.999 9. The
relative standard deviations (RSD) are 4.2%, 1.9%, 1.4% and 0.81% for 0.005, 0.05, 0.5 and 5.0 mg/L of formaldehyde,
respectively. The limit of detection (LOD) was 0.025 mg/kg for solid and powder samples, and 0.025 mg/L for liquid
samples. The method described here was applied to the analysis of dried mushroom samples, wheat flour samples and beer
samples, and the recoveries of formaldehyde obtained were in the range of 92.0%–97.7% with relative standard deviations
(RSD) lower than 5.6%. The results showed that the proposed method was highly selective, rapid, convenient and reliable
and could be used for the determination of formaldehyde in food samples.