摘要
以青菜和马铃薯为供试蔬菜,在建立蔬菜中三聚氰胺液相色谱串联质谱(LC-MS-MS)测定方法的基础上,采用N15同位素稀释法,通过在土壤中添加三聚氰胺进行盆栽试验,研究了三聚氰胺在土壤中的降解动态及两种蔬菜的吸收效应。结果表明,土壤中三聚氰胺降解速率随着土壤中三聚氰胺质量比的增加而变慢,20 d以后,降解曲线平缓,速度缓慢,残留时间延长,其降解动态符合Logistic方程。同位素稀释法证实两种蔬菜均可以吸收土壤中的三聚氰胺。当土壤中含有50mg/kg和100mg/kg三聚氰胺时,马铃薯的吸收量分别比青菜高4.4和2.1倍。青菜根部对三聚氰胺的吸收高于茎叶。高质量比三聚氰胺对蔬菜生长具有明显的抑制效应。
The given paper intends to introduce its study on the degradation and absorption of melamine in the soil and vegetables. For this purpose, we have developed a liquid chromatography tandem mass spectrometry （LC -MS- MS） to determine the melamine in the vegetable through testing it in the greens and potatoes. To achieve our purpose, we have designed and conducted the soil pot experiments by adding melamine in them with the method of N15 isotope dilution in hoping to test the above mentioned effects. The experimental sample we have adopted can be separated via a WCX （3.0 mm x 50 mm, 3 ttm） column by means of aeetonitrile and 10mmol ammonium acetate as the mobile phase, whose flowing rate is 350 gL/min at the mobile phase of pH ^- 4, with its injection volume being 10 /IL. Under the above experimental conditions, it has been found that the optimal spiked recovery rate of melamine tends to be 82.6 % - 90.7 % in the range of 0.2 - 50 mg/kg with the coefficient of variation being 0.76% - 2.78% . The pot experiment results of ours show that with the increase of melamine concentration, the degradation rate of the melamine in the soil tends to be slow while the degradation curve changes gently with the degradation speed going slowly till the residu- al time prolongs over 20 days. Needless to say, it is in conformity with the degradation dynamics of the Logistic Equation. However, so far as the content of the plants in our pot experiments is concerned, the melamine and N15-melamine detection, the proportion of NIs- melamine in all the melamine content proves to be in line with the ra- tio added in the soil, indicating that the melamine detected in the plants indeed comes from the soil. Thus, it can be seen that the iso- tope dilution results confirm that vegetables can absorb melamine in the soil, which inhibit their growth. Moreover, the higher the con- centration of melamine in the soil, the stronger the effect of the inhi- bition. And, with the increased treatment of melamine in the soil, the absorption of greens and potatoes for melamine also tends to in- crease. Besides, we have also found that the content of melamine in the roots of the greens turns to be richer than in the leaves. The abili- ty of plants to absorb melamine varies greatly, too. In this experiment, the absorption of potatoes for the melamine proves to be higher than greens at the same concentration.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第6期13-17,共5页
Journal of Safety and Environment
基金
上海市科技兴农重点攻关项目(沪农科攻字2010第2-3号)
国家检验检疫行业标准制订计划项目(20091851-T-606)
关键词
环境科学技术基础学科
蔬菜
土壤
三聚氰胺
降解
吸收
basic disciplines of environmental science and technolo- gy
vegetables
soil
melamine
degradation
absorption
