Comparative measurements of mineral elements in milk powders with laser-induced breakdown spectroscopy and inductively coupled plasma atomic emission spectroscopy

• Published in: Analytical and bioanalytical chemistry Vol. 400; no. 10; pp. 3303 - 3313
• Main Authors: Lei, W. Q., El Haddad, J., Motto-Ros, V., Gilon-Delepine, N., Stankova, A., Ma, Q. L., Bai, X. S., Zheng, L. J., Zeng, H. P., Yu, J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.07.2011; Springer; Springer Verlag
• Subjects: Analytical Chemistry; Animals; Biochemistry; Biochemistry, Molecular Biology; Characterization and Evaluation of Materials; Chemical Sciences; Chemistry; Chemistry and Materials Science; Comparative analysis; Elements; Emission analysis; Food Analysis - methods; Food Analysis - standards; Food Science; Inductively coupled plasma; Laboratory Medicine; Laser ablation; Lasers; Life Sciences; Mathematical analysis; Metals - analysis; Methods; Milk; Milk - chemistry; Minerals; Minerals - analysis; Monitoring/Environmental Analysis; Original Paper; Plasmas; Powders; Spectroscopy; Spectrum analysis; Spectrum Analysis - methods; Spectrum Analysis - standards; ICP-AES; Milk powder; CF-LIBS; Matrix effect; LIBS; SOILS; AIR; QUANTITATIVE-ANALYSIS; TRACE-ELEMENTS; ALLOYS; SELF-ABSORPTION; SAMPLES; SPECTROMETRY
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-011-4813-x

Mineral elements contained in commercially available milk powders, including seven infant formulae and one adult milk, were analyzed with inductively coupled plasma atomic emission spectrometry (ICP-AES) and laser-induced breakdown spectroscopy (LIBS). The purpose of this work was, through a direct comparison of the analytical results, to provide an assessment of the performance of LIBS, and especially of the procedure of calibration-free LIBS (CF-LIBS), to deal with organic compounds such as milk powders. In our experiments, the matrix effect was clearly observed affecting the analytical results each time laser ablation was employed for sampling. Such effect was in addition directly observed by determining the physical parameters of the plasmas induced on the different samples. The CF-LIBS procedure was implemented to deduce the concentrations of Mg and K with Ca as the internal reference element. Quantitative analytical results with CF-LIBS were validated with ICP-AES measurements and nominal concentrations specified for commercial milks. The obtained good results with the CF-LIBS procedure demonstrate its capacity to take into account the difference in physical parameters of the plasma in the calculation of the concentrations of mineral elements, which allows a significant reduction of the matrix effect related to laser ablation. We finally discuss the way to optimize the implementation of the CF-LIBS procedure for the analysis of mineral elements in organic materials.