食用菌中甲醛的提取和乙酰丙酮分光光度法分析

Extraction of formaldehyde in edible mushrooms and determination by acetylacetone spectrophotometry

目的建立适用于多种食用菌的甲醛提取技术和甲醛含量的乙酰丙酮分光光度法测定技术。方法研究灭酶处理、浸泡时间和温度对食用菌样品中甲醛提取的影响,并用凯氏定氮仪蒸馏单元对处理后的食用菌样品进行水蒸汽蒸馏,替代了直接蒸馏法。结果食用菌鲜样和干样粉碎后直接用水蒸汽蒸馏提取,能快速提取样品中的甲醛,并能反映样品真实的甲醛含量;甲醛在1μg/ml浓度内呈线性相关,相对标准偏差（RSD）〈10%（n=5）,回收率为82.10%~97.98%。结论本方法快速简便、准确度高、精密性好,适用于多种食用菌中甲醛含量的分析。

Objective To establish a method of extraction and contentanalysis by acetylacetone spectrophotometry for formaldehyde in several edible mushrooms. Methods Mushroom samples were extracted by steam distillation with the distillation unit of Kieldahl azotometer instead of direct distillation. Furthermore, the effects of enzyme inactivation, soaking time and temperature on formaldehyde extraction were studied. Results Both in fresh and dried mushroom samples, formaldehyde could be fully extracted in several minutes by direct steam distillation after triturating, and the exact contents of formaldehyde were reflected by the extraction treatment. The linear range for formaldehyde was 0-1 p,g/ml, and the method showed good accuracy with RSD 〈 10% （n =5） and recovery rate ranged from 82.10% to 97, 98%. Conclusion The method established in the study is efficient, simple, accurate, precise and suitable for analysis formaldehyde contents in a variety of edible mushrooms.