Alvarez-Fernández Ana, Orera Irene, Abadía Javier, Abadía Anunciación
Plant Nutrition Department, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (CSIC), Zaragoza, Spain.
J Am Soc Mass Spectrom. 2007 Jan;18(1):37-47. doi: 10.1016/j.jasms.2006.08.018. Epub 2006 Sep 28.
A high-performance liquid chromatography-electrospray ionization/mass spectrometry (time of flight) method has been developed for the simultaneous determination of synthetic Fe(III)-chelates used as fertilizers. Analytes included the seven major Fe(III)-chelates used in agriculture, Fe(III)-EDTA, Fe(III)-DTPA, Fe(III)-HEDTA, Fe(III)-CDTA, Fe(III)-o,oEDDHA, Fe(III)-o,pEDDHA, and Fe(III)-EDDHMA, and the method was validated using isotope labeled (57)Fe(III)-chelates as internal standards. Calibration curves had R values in the range 0.9962-0.9997. Limits of detection and quantification were in the ranges 3-164 and 14-945 pmol, respectively. Analyte concentrations could be determined between the limits of quantification and 25 muM (racemic and meso Fe(III)-o,oEDDHA and Fe(III)-EDDHMA) or 50 muM (Fe(III)-EDTA, Fe(III)-HEDTA, Fe(III)-DTPA, Fe(III)-CDTA and Fe(III)-o,pEDDHA). The average intraday repeatability values were approximately 0.5 and 5% for retention time and peak area, respectively, whereas the interday repeatability values were approximately 0.7 and 8% for retention time and peak area, respectively. The method was validated using four different agricultural matrices, including nutrient solution, irrigation water, soil solution, and plant xylem exudates, spiked with Fe(III)-chelate standards and their stable isotope-labeled corresponding chelates. Analyte recoveries found were in the ranges 92-101% (nutrient solution), 89-102% (irrigation water), 82-100% (soil solution), and 70-111% (plant xylem exudates). Recoveries depended on the analyte, with Fe(III)-EDTA and Fe(III)-DTPA showing the lowest recoveries (average values of 87 and 88%, respectively, for all agricultural matrices used), whereas for other analytes recoveries were between 91 and 101%. The method was also used to determine the real concentrations of Fe(III)-chelates in commercial fertilizers. Furthermore, the method is also capable of resolving two more synthetic Fe(III)-chelates, Fe(III)-EDDHSA and Fe(III)-EDDCHA, whose exact quantification is not currently possible because of lack of commercial standards.
已开发出一种高效液相色谱 - 电喷雾电离/质谱（飞行时间）方法，用于同时测定用作肥料的合成铁（III）螯合物。分析物包括农业中使用的七种主要铁（III）螯合物，即铁（III）-乙二胺四乙酸（Fe(III)-EDTA）、铁（III）-二乙三胺五乙酸（Fe(III)-DTPA）、铁（III）-羟乙基乙二胺三乙酸（Fe(III)-HEDTA）、铁（III）-环己烷二胺四乙酸（Fe(III)-CDTA）、铁（III）-邻，邻 - 乙二胺二邻羟基苯基乙酸（Fe(III)-o,oEDDHA）、铁（III）-邻，对 - 乙二胺二邻羟基苯基乙酸（Fe(III)-o,pEDDHA）和铁（III）-乙二胺二邻羟基苯基乙酸（Fe(III)-EDDHMA），该方法使用同位素标记的（57）Fe(III) - 螯合物作为内标进行了验证。校准曲线的R值在0.9962 - 0.9997范围内。检测限和定量限分别在3 - 164和14 - 945皮摩尔范围内。分析物浓度可在定量限和25μM（外消旋和内消旋Fe(III)-o,oEDDHA以及Fe(III)-EDDHMA）或50μM（Fe(III)-EDTA、Fe(III)-HEDTA、Fe(III)-DTPA、Fe(III)-CDTA和Fe(III)-o,pEDDHA）之间测定。日内重复性的保留时间和峰面积平均值分别约为0.5%和5%，而日间重复性的保留时间和峰面积平均值分别约为0.7%和8%。该方法使用四种不同的农业基质进行了验证，包括营养液、灌溉水、土壤溶液和植物木质部渗出液，这些基质中添加了铁（III）螯合物标准品及其稳定同位素标记的相应螯合物。发现的分析物回收率在92 - 101%（营养液）、89 - 102%（灌溉水）、82 - 100%（土壤溶液）和70 - 111%（植物木质部渗出液）范围内。回收率取决于分析物，Fe(III)-EDTA和Fe(III)-DTPA的回收率最低（对于所有使用的农业基质，平均值分别为8
