Andrade Daniel F, Pereira-Filho Edenir Rodrigues
Grupo de Análise Instrumental Aplicada (GAIA), Departamento de Quı́mica (DQ), Centro de Ciências Exatas e de Tecnologia (CCET), Universidade Federal de São Carlos (UFSCar) , P.O. Box 676, São Carlos, São Paulo State 13565-905, Brazil.
J Agric Food Chem. 2016 Oct 19;64(41):7890-7898. doi: 10.1021/acs.jafc.6b04028. Epub 2016 Oct 11.
Contaminants (Cd, Cr, and Pb) as well as minor (B, Cu, Mn, Na, and Zn) and major (Ca and Mg) elements were directly determined in solid fertilizer samples using laser-induced breakdown spectroscopy (LIBS). Factorial designs were used to define the most appropriate LIBS parameters and pellet pressure on solid fertilizers. Emission lines for all of the analytes were collected and employed 12 signal normalization modes. The best results were obtained using a laser energy of 75 mJ, a spot size of 50 μm, a pressure of 10 t/in., and a delay of 2.0 μs. Good correlation was obtained between the calibration model's prediction using the proposed LIBS method and the reference values obtained with ICP-OES. The limits of detection (LOD) for the proposed method varied from 2 mg/kg (for Cd) to 1% (for Zn).
采用激光诱导击穿光谱法（LIBS）直接测定固体肥料样品中的污染物（镉、铬和铅）以及微量元素（硼、铜、锰、钠和锌）和常量元素（钙和镁）。采用析因设计来确定固体肥料最合适的LIBS参数和压片压力。收集所有分析物的发射线并采用12种信号归一化模式。使用75 mJ的激光能量、50μm的光斑尺寸、10 t/in.的压力和2.0μs的延迟可获得最佳结果。使用所提出的LIBS方法的校准模型预测值与电感耦合等离子体发射光谱法（ICP-OES）获得的参考值之间具有良好的相关性。所提出方法的检测限（LOD）从2 mg/kg（对于镉）到1%（对于锌）不等。
