Publicação
Determination of nitrate and nitrite in dairy samples by sequential injection using an in-line cadmium-reducing column
| Resumo: | A sequential injection analysis (SIA) system for the spectrophotometric determination of nitrate in dairy samples was developed. A test portion was aspirated into a carrier solution containing ethylendiaminetetracetic acid (EDTA) and ammonium buffer, which flowed into a copperized cadmium reduction column installed in-line for the determination of the nitrate plus nitrite contents of samples. For the nitrite determination, another test portion of sample was aspirated and directly sent to the detector without reduction. Nitrate content was calculated from the difference between nitrate plus nitrite (expressed as nitrite) and nitrite content. The spectrophotometric determination is based on the Griess reaction. The proposed method was used to test several dairy samples (ultrapasteurized milk with 1.7% milk fat, whey, raw bovine milk and several cheese varieties). Results were statistically in good agreement with those provided by the reference procedure, with a detection limit of 0.15 mgL 1. A sampling rate of 21 determinations per hour can be achieved with this procedure. |
|---|---|
| Autores principais: | Lima, M. J. Reis |
| Outros Autores: | Fernandes, Sílvia M.V.; Rangel, António O.S.S. |
| Assunto: | Sequential injection Copperized cadmium column Nitrate Nitrite Dairy samples |
| Ano: | 2006 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade Católica Portuguesa |
| Idioma: | inglês |
| Origem: | Veritati - Repositório Institucional da Universidade Católica Portuguesa |
| Resumo: | A sequential injection analysis (SIA) system for the spectrophotometric determination of nitrate in dairy samples was developed. A test portion was aspirated into a carrier solution containing ethylendiaminetetracetic acid (EDTA) and ammonium buffer, which flowed into a copperized cadmium reduction column installed in-line for the determination of the nitrate plus nitrite contents of samples. For the nitrite determination, another test portion of sample was aspirated and directly sent to the detector without reduction. Nitrate content was calculated from the difference between nitrate plus nitrite (expressed as nitrite) and nitrite content. The spectrophotometric determination is based on the Griess reaction. The proposed method was used to test several dairy samples (ultrapasteurized milk with 1.7% milk fat, whey, raw bovine milk and several cheese varieties). Results were statistically in good agreement with those provided by the reference procedure, with a detection limit of 0.15 mgL 1. A sampling rate of 21 determinations per hour can be achieved with this procedure. |
|---|
Atividades financiadas
Não foram encontrados projetos financiados.