有机-无机复混肥中有机质测定方法的比较研究

Comparison of determination methods of organic matter content of organic-inorganic compound fertilizers

采用稀释热法、沸水浴法和油浴法分别测定有机-无机复混肥的有机质含量,并比较了3种方法的精度与准确度。结果表明：沸水浴法和油浴法测定复混肥有机质的相对标准偏差（RSD）和回收率均符合实验要求,值得推广应用;而稀释热法的相对标准偏差（RSD）随着复混肥有机质含量的增加呈上升趋势,为0.55%~6.24%,且单个样品回收率有时超出100%±5%范围。与沸水浴法和油浴法相比,稀释热法的稳定性和准确性相对较差。同时,本研究以灼烧法为参照方法得出稀释热法、沸水浴法、油浴法测定有机-无机复混肥有机质含量的氧化校正系数分别为1.63、1.49、1.24,高于用此3种方法测定土壤有机质含量时的氧化校正系数。

Dilution-heating method,boiling bath method and oil bath method were used to determine organic matter content of organic-inorganic compound fertilizers,and the precision and accuracy of the three methods compared.The relative standard deviation（RSD）and recovery rate of both boiling bath method and oil bath method are within acceptable range.However,dilution-heating method RSD is 0.55%～6.24%,and enhances with increase of organic matter content in organic-inorganic compound fertilizer.And in some organic-inorganic compound fertilizer samples,the dilution-heating method recovery rate is beyond 100%±5%.Thus in comparison with the boiling bath and oil bath methods,stability and veracity of the dilution-heating method are relatively lower.Adjusted oxidation coefficient of measured organic matter contents of organic-inorganic compound fertilizers under dilution-heating,boiling bath method and oil bath method is 1.63,1.49,1.24 respectively;much higher than that of measured organic matter content of soil.