Determinations of phosphorus in fertilizers by spark discharge-assisted laser-induced breakdown spectroscopy
| Autor: | Edilene Cristina Ferreira, Felipe Schiavon Inocencio de Sousa, Tiago Varão Silva, Dário Santos Júnior, Giorgio S. Senesi, Alan Lima Vieira, José Anchieta Gomes Neto |
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| Přispěvatelé: | Universidade Estadual Paulista (Unesp), Universidade de São Paulo (USP), CNR-Istituto di Nanotecnologia (NANOTEC) – PLasMI Lab |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
LIBS Phosphorus determination Calibration curve 010401 analytical chemistry Analytical chemistry 02 engineering and technology Spark discharge 021001 nanoscience & nanotechnology Laser 01 natural sciences Fluence 0104 chemical sciences Analytical Chemistry law.invention law Fertilizer analysis Electrode Electric discharge Laser-induced breakdown spectroscopy 0210 nano-technology Atomic absorption spectroscopy Spectroscopy |
| Zdroj: | Scopus Repositório Institucional da UNESP Universidade Estadual Paulista (UNESP) instacron:UNESP |
| Popis: | Made available in DSpace on 2018-12-11T17:36:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-06-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A spark discharge system was coupled to laser-induced breakdown spectroscopy (SD-LIBS) to improve sensitivity in the determination of P in fertilizers. A LIBS system consisting of a Q-switched Nd:YAG laser operating at 1064 nm and emitting pulses at 50 mJ with a fluence of 70 J cm−2 at the focal point was used. Results of preliminary experiments suggested that the most appropriate wavelength to measure P was the P (I) line at 214.9 nm, which did not show interferences by Fe, Cu and Zn. The electrical discharge was provided by a homemade high-voltage electronic circuit consisting of two cylindrical tungsten electrodes at the optimized output voltage of 4.5 kV, with tips arranged at the optimal distances of 4 mm between them and 2 mm above the sample surface. To minimize the expected matrix effects calibration standards of P2O5 in the range of 4.8 and 33.3% were prepared by mixing various amounts of a phosphate rock reference material (SRM-120c) with a mixture of CaCO3, CaSO4, (NH2)2CO and KCl at a 1:1:1:1 mass ratio. The calibration curves obtained at a 4.5 kV SD-LIBS output voltage showed correlation coefficients ≥0.993, RSD ≤8% and LOQ 5.3% (m/m) P2O5. Data obtained by analyzing commercial samples by the proposed system were in good agreement, at 95% confidence level, with those obtained by using high-resolution continuum-source flame atomic absorption spectroscopy. São Paulo State University - UNESP Analytical Chemistry Department, P.O. Box 355 University of São Paulo – USP Department of Electrical and Computer Engineering CNR-Istituto di Nanotecnologia (NANOTEC) – PLasMI Lab, Via Amendola 122/D Federal University of São Paulo - UNIFESP Exact and Earth Sciences Department São Paulo State University - UNESP Analytical Chemistry Department, P.O. Box 355 CNPq: 141977/2016-7 FAPESP: 2004/14212-0 CNPq: 2015/24757-9 CNPq: 303255/2013-7 CNPq: 311085/2014-8 |
| Databáze: | OpenAIRE |
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