摘要:本課題采用國標(biāo)法，微波法及超聲—微波協(xié)同萃取法這三種提取方法提取蔬菜中亞硝酸鹽，并對提取條件進(jìn)行了單因素和正交實驗。實驗確定料液比、功率、時間對微波法的影響以及料液比、功率、時間、溫度、提取劑和活性炭加入量對超聲—微波協(xié)同萃取法的影響。結(jié)果表明，超聲—微波協(xié)同萃取法提取效果最優(yōu)，反應(yīng)料液比為1:15，反應(yīng)時間為6 min，反應(yīng)功率為50 w為其最佳實驗條件，可用于實際樣品中亞硝酸鹽的提取。

　　　用超聲—微波協(xié)同萃取法在最佳條件下對樣品進(jìn)行測定，其測定結(jié)果與國標(biāo)和微波法測定結(jié)果相比較，提取率分別增加了61.40%~95.73%和23.58%~32.10%。測定的相對標(biāo)準(zhǔn)偏差為1.04%~4.52%，加標(biāo)回收率在97.28%~104.76%之間。用實際樣品進(jìn)行測定，測得的7種葉類蔬菜中亞硝酸鹽含量在1.3643~1.7708 mg/kg之間，均在亞硝酸鹽限量衛(wèi)生標(biāo)準(zhǔn)所規(guī)定的范圍之內(nèi)。

關(guān)鍵詞 亞硝酸鹽；國標(biāo)法；微波法；超聲—微波協(xié)同萃取法

Abstract:The topic uses national standard method, microwave method and ultrasonic-microwave extraction method to extract nitrite in vegetables, through single factors and orthogonal experiments to determine the influence of the material liquid ratio, power, time on microwave method and the influence of the material liquid ratio, power, time, temperature, extraction reagent and the amount of activated carbon on ultrasound-microwave collaborative extraction method. Results show that the material liquid ratio of 1:15 and reaction time of 6 min and reaction power of 50w are the best experimental conditions, which can be used to extract nitrite in actual samples. 

　　　Using ultrasonic-microwave collaborative extraction method to test samples under the best conditions, the relative standard deviation is between 1.04% and 1.04%, standard addition recovery rate is between 97.28% and 104.76%. When compared with national standard method and microwave method, extraction yield increases by 61.40% ~ 95.73% and 23.58% ~ 61.40% respectively. Meanwhile, nitrite tested in vegetables is between 1.3643 and 1.7708 mg/kg, which are all under control of standards.

Keywords nitrite the national standard extraction method the microwave method the ultrasonic-microwave collaborative extraction method