柱前衍生高效液相色谱法测定5种常见食用菌中的甲醛含量

Determination of formaldehyde in 5 kinds of common edible fungi by pre-column derivatization-high performance liquid chromatography

目的建立柱前衍生-高效液相色谱法测定5种常见食用菌中甲醛含量。方法将干制与新鲜食用菌用超纯水浸泡,浸泡液经2,4-硝基苯肼(DNPH)衍生后,采用高效液相色谱法检测;色谱柱:C18(250 mm×4.6 mm,5μm),流动相:乙腈-水(70:30,V:V);流速为1.0 mL/min;检测波长352 nm;柱温40℃。外标法定量测定食用菌中甲醛含量。结果柱前衍生法对甲醛浓度在10.70~214.00μg/L范围内与其衍生物峰面积呈良好的线性关系,线性回归系数(r2)为0.9964,方法的检出限为4.20μg/kg(S/N=3)。加标回收率为78.27%~114.26%,精密度1.55%~9.22%(n=6)。5种食用菌样品仅香菇样品检出甲醛。新鲜香菇甲醛含量超标,干制后香菇甲醛含量降低,低至国家标准含量以下。结论本研究的方法简便、快速、准确、稳定,可用于测定食用菌中甲醛含量。

Objective To establish a method for determination of formaldehyde content in 5 kinds of common edible fungi by pre-column derivatization-high performance liquid chromatography. Methods The dried and fresh edible fungus were soaked with ultra-pure water, the solution was derived from 2,4-nitrophenylhydrazine (DNPH) and detected by high performance liquid chromatography (HPLC). Chromatographic column was C18 (250 mm×4.6 mm, 5 μm), mobile phase was 70% acetonitrile and 30% water, and flow rate was 1.0 mL/min. The detection wavelength was 352 nm. The column temperature was 40 ℃. The external standard method was used to quantitatively detect the formaldehyde in edible fungi. Results The calibration curve of the concentration of formaldehyde showed good linearity within 10.70-214.00 μg/L, with the linear regression coefficient (r 2 ) was 0.9964, and the limit of detection of the method was 4.20 μg/kg (S/N=3). The average recoveries were 78.27%-114.26%, and the relative standard deviations were 1.55%-9.22%(n=6). Formaldehyde was detected only in mushrooms. The formaldehyde content in fresh mushrooms was exceed, but the formaldehyde content in dried mushrooms was reduced and below the national standards. Conclusion This method is simple, rapid, accurate and stable, which can be used to determine the content of formaldehyde in edible fungi.