Direct determination of calcium and phosphorus in mineral supplements for cattle by wavelength dispersive X-ray fluorescence (WD-XRF)

• Published in: Microchemical journal 2018-03, Vol.137, p.272-276
• Main Authors: Babos, Diego Victor, Costa, Vinícius Câmara, Sperança, Marco Aurelio, Pereira-Filho, Edenir Rodrigues
• Format: Article
• Language: English
• Subjects: Animal nutrition; Matrix-matching; Mineral supplements for cattle; Solids direct analysis; WD-XRF
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2017.11.002

The current study describes a simple and rapid method for the direct determination of Ca and P in mineral supplements for cattle by wavelength dispersive - X-ray fluorescence (WD-XRF). For calibration, solid standards obtained through a set of reference materials (RMs) of mineral supplements for cattle with concentrations of Ca ranged from 120 to 223gkg−1 (r=0.9809) and P ranged from 29 to 95gkg−1 (r=0.9957) were used. For Ca, the matrix-matching using the RM 18/03 diluted in Na2CO3: NaCl (1:1 w/w) in the range of 0–204gkg−1 (r=0.9975) was also used as calibration strategy. The proposed method presented limits of detection of 47mgkg−1 for Ca and 36mgkg−1 for P using calibrations with RMs and 61mgkg−1 to Ca using matrix-matching calibration strategy. Accuracy was assessed by the analysis of four RM of mineral supplements for cattle. A statistical evaluation using student's t-test showed that there is no significant difference between the value obtained with the proposed method and the certified value, at 95% confidence level. The method was successfully applied and is a good alternative to conventional acid digestion routine analysis for determination of Ca and P in mineral supplements for cattle. •Direct analysis of mineral supplements using X-ray fluorescence•Calcium and phosphorus determination using different calibration strategies•Mineral supplements quality control observing the ratio between Ca and P