微波密闭增压浸提柑桔园土壤中水溶态硼

Pressurized Extraction of Water-Soluble Boron in Soil of Orange Grove in Tightly Closed PTFE Vessel by Micro-Wave Assisted Heating

提出了在微波炉加热用水提取土壤中水溶态硼的处理方法,采用的辐射功率为1.36kW,加热提取过程分先后两步:①在0.1MPa压力下加热90s,②在0.2MPa压力下加热125s。从某柑桔园中采得土壤样品12个,分别按回流浸提法和微波消解法提取其水溶态硼并用石墨炉原子吸收光谱法(GF-AAS)测定其含量,两种提取方法所测结果的一元回归方程的相关系数为0.991,对该回归方程斜率和截距进行t检验,表明两种方法所得的水溶态硼量之间无显著差异(置信水平95%)。取同一试样5份,分别按所述方法提取其水溶态硼并按GF-AAS法测定,计算分析结果的相对标准偏差(n=5)为3.4%(微波消解法)和5.7%(回流浸提法)。

Extraction of water soluble boron in soil with water by heating in a micro-wave digestion oven was proposed. Radiation power of 1.36 kW was used and a program of heating under pressure in 2 successive steps was adopted in the procedure, i. e. ： （1） at 0. 1 MPa for 90 s and （2） at 0. 2 MPa for 125 s. Twelve soil samples taken from the orange grove and their water soluble boron were extracted separately by the micro-wave digestion and refluxing methods. Correlativity of the data obtained by the 2 methods, as determined by GF-AAS, was tested, giving value of correlation coefficient of 0. 991 for the linear regression equation. It was shown by the t-test for the slope and intercept of the linear regression equation that no significant difference was found between the proposed extraction metbod and the refluxing method under the confidence level of 95 %. In the determination of soluble boron in a soil sample by GF-AAS for 5 times with treatment of sample by the 2 methods mentioned above, values of RSD＇s （n=5） obtained were 3. 4% （by micro-wave digestion） and 5. 7% （by refluxing）.