Determination of water in organic fertilizer by gas chromatography
Gan Hezhi, Zhang Haiyin, Li Fu
Guangxi Zhuang Autonomous Region Testing Institute of Product Quality, Nanning 530000, China
摘要：建立气相色谱法测定有机肥料中水分含量的方法。样品在N，N-二甲基甲酰胺中超声提取，采用porapad-Q多孔高分子小球不锈钢填充柱（1 m×4 mm，177～250 μm）为分离色谱柱，加入甲醇作为内标物，以热导检测器检测，内标法定量。结果表明，样品提取液中水的含量在0.00～77.85 mg/g范围内与色谱峰面积呈良好的线性关系，相关系数为0.999 6。样品测定结果的相对标准偏差为0.79%～3.98%（n=7），加标回收率为95.3%～101.3%。该方法准确度高，重现性好，适用于有机肥料中水分含量的定量分析。
Abstract：A method was established for determining water content in organic fertilizer by gas chromatography with thermal conductivity detector. The samples were extracted in N, N-dimethyl formamide by ultrasound. The porapad-Q stainless steel chromatographic column packed with porous polymer microsphere(1 m×4 mm, 177-250 μm) was used as the separation column. Methanol was added as the internal standard for detection by thermal conductivity detector. The results showed that the water content had a good linear relationship with chromatographic peak area in the range of 0.00-77.85 mg/g, the correlation coefficient were 0.999 6. The relative standard deviations of determination results of samples were 0.79%-3.98%(n=7), and the recoveries were 95.3%-101.3%. The method has high accuracy and good reproducibility, which is recommended for the quantification of water content in organic fertilizer.
Keywords：organic fertilizer; determination of water content; gas chromatography
Gan Hezhi，Zhang Haiyin，Li Fu. Determination of water in organic fertilizer by gas chromatography[J]. Chemical Analysis and Meterage，2021，30(11)：55.