Automatic determination of fat in milk by use of a flow injection system with a piezoelectric detector
- Manganiello, Lisbeth . 2
- Ríos, A. 2
- Valcárcel, M. 2
- Ligero, A. 2
- Tena, T. 1
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1
Universidad de La Rioja
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2
Universidad de Córdoba (Colombia)
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ISSN: 0003-2670
Año de publicación: 2000
Volumen: 406
Número: 2
Páginas: 309-315
Tipo: Artículo
Otras publicaciones en: Analytica Chimica Acta
Resumen
A new method for the direct determination of total fat in milk by use of a quartz crystal microbalance was developed. The method is based on a (micro) extraction procedure that is carried out in a flow injection system. Samples are diluted with an ethanol-water mixture and injected into the flow system, where they are mixed with n-hexane in an extraction coil. The analyte is determined in the organic phase. The calibration thus achieved is linear in the range 0.20-0.45% w/v, and the relative standard deviation is ±3.2% (n=11; P=0.05). The throughput is 12 samples per hour. The proposed method was used to determine fat matter in milk samples; the results were found to be competitive with those of official methods for the same purpose. Copyright (C) 2000 Elsevier Science B.V.