Potential Application of Laser‐Induced Breakdown Spectroscopy (LIBS) Data for the Determination of Cation Exchange Capacity (CEC) of Agricultural Soils

Abstract

The potential for Laser Induced Breakdown Spectroscopy (LIBS) technique to predict cation exchange capacity (CEC) values in agricultural soils, based on a partial least square (PLS) regression model, was investigated by analysing soils (N = 225) using a portable LIBS system. The prediction from the validation set was 0.75 and the RMSE was 5.4 cmol + /kg. Analysis of the PLS loading weights showed that emission lines that correlate with the exchangeable cations (Ca, Mg, K and Na) and clay (Al and Si) are significant. Good quality predictions could be obtained from the model as described by the ratio of performance to deviation (RPD) values calculated for calibration (RPDc = 1.99) and validation (RPDv = 2.02). The ratio of performance to interquartile distance (RPIQ) for calibration (RPIQc = 3.20) and validation (RPIQv = 3.32) indicated excellent prediction capability. It has been demonstrated that LIBS spectra coupled with multivariate data analysis could be used to predict CEC of agricultural soils which is considered fast and a chemical-free technique.[a] M. C. Pelagio

Atomic spectrometry update – a review of advances in environmental analysis

“…Huang 224 proposed a zircon megacryst (SA01-A) as a new RM for microbeam U-Pb geochronology and Hf and O isotope geochemistry. A mean 206 Pb/ 238 U age of 535.08 AE 0.32 Ma was determined by CA-ID-TIMS, a d 18 O value of 6.16 AE 0.26& by laser uorination and a mean 176 Hf/ 177 Hf ratio of 0.282293 AE 0.000007 by solution MC-ICP-MS. Although the megacryst was homogeneous for these measurements, it had signicant spatial variations in Th/ U and Li isotope ratios.…”

“…The practical lower limit for the 180 Hf intensity was set at ca. 1 V so that meaningful 176 Hf/ 177 Hf ratios and <1.5 3 unit internal errors could be achieved simultaneously. Zircon was also the focus of a study which reported 290 a protocol for in situ determinations of stable Zr isotope ratios by LA-MC-ICP-MS.…”

“…There has been continued interest in the prediction of soil properties based on chemometric processing of LIBS data . Methods were reported for cation exchange capacity 177 based on PLSR, soil pH 178 based on the RF model, and soil texture 179 (proportions of sand, silt and clay) based on PLSR and the elastic net algorithm.…”