AA3型连续流动分析仪与钒钼黄比色法测定玉米植株全磷含量之比较

选择69个玉米秸秆和籽粒样品,经浓H₂SO₄和H₂O₂消煮后,用连续流动分析仪与钒钼黄比色法分别测定消煮液中磷含量,对2种方法检测数据之间进行比较分析,探讨利用连续流动分析仪测定植株样品消煮液中磷含量的可行性。t检验表明:2种方法测定植株全磷含量相比无明显差异。测定结果之间呈显著线性相关系,回归直线方程为Y(连续流动分析仪-P)=0.927X(钒钼黄比色法-P)-0.002,相关系数r=0.985(n=69,P<0.01)。连续流动分析仪测定加标回收率在99.3%~103.8%之间,对4个样品消煮液中磷浓度分别重复测定10次,相对标准偏差小于1.5%。连续流动分析仪分析速度快,消耗试剂少,推荐用于大批量玉米植株样品H₂SO₄-H₂O₂消煮液中磷含量分析。

Determination Total Phosphour of Maize Plant Samples by Continuous Flow Analyzer in Comparison with Vanadium Molybdate Yellow Colorimetric Method

The vanadium molybdate yellow colorimetric method(VMYC method) is regarded as one of conventional methods for determining total phosphorus(P) in plants, but it is time consuming procedure. Continuous flow analyzer(CFA) is a fluid stream segmentation technique with air segments. It is used to measure P concentration based on the molybdate-antimony-ascorbic acid method of Murphy and Riley. Sixty nine of maize plant samples were selected and digested with H₂SO₄-H₂O₂. P concentrations in the digests were determined by CFA and VMYC method, respectively. The t test found that there was no any significant difference of the plant P contents measured by the CFA and the VMYC method. A linear equation could best describe their relationship: Y(CFA-P)=0.927X(VMYC-P)-0.002. The Pearson's correlation coefficient was 0.985 with a significance level(n=69, P<0.01). The CFA method for plant P measurement had a high precision with relative standard deviation(RSD) less than 1.5%. It is suggested that the CFA based on Murphy and Riley colorimetric detection can be used to determinate total plant P in the digests solutions with H₂SO₄-H₂O₂. The CFA method is labor saving and can handle large numbers of samples. The human error in mixing with other operations is reduced to a great extent.