|
|
|
|
|
| Malafatti,Lusiane; Maia,Patrícia Penido; Martins,Matheus Coutinho Gonçalves; Siqueira,Maria Elisa Pereira Bastos de; Martins,Isarita. |
| Nicotine is a major addictive compound in cigarettes and is rapidly and extensively metabolized to several metabolites in humans, including urinary cotinine, considered a biomarker due to its high concentration compared to other metabolites. The aim of this study was to develop a single method for determination of urinary cotinine, in active and passive smokers, by gas chromatography with a nitrogen phosphorus detector (GC-NPD). Urine (5.0 mL) was extracted with 1.0 mL of sodium hydroxide 5 mol L-1, 5.0 mL of chloroform, and lidocaine used as the internal standard. Injection volume was 1 μL in GC-NPD. Limit of quantification was 10 ng mL-1. Linearity was evaluated in the ranges 10-1000 ng mL-1 and 500-6000 ng mL-1, with determination coefficients of 0.9986... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gas chromatography/with nitrogen phosphorus detector; Urinary cotinine/determination; Urine/toxicological analysis; Smokers/Toxicology. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502010000400019 |
| |
|
|
| Kujbida,Paula; Maia,Patrícia Penido; Araújo,Ariadne Naama de; Mendes,Leonardo Daniel; Oliveira,Mariana Lepri de; Silva-Rocha,Walicyranison Plinio; Brito,George Queiroz de; Chaves,Guilherme Maranhão; Martins,Isarita. |
| In the present study, the occurrence of fungi and aflatoxins (AFs) in peanut and cashew nut samples was investigated. Mycological analysis revealed the presence of fungi in 58.8% of samples, and assessment of AFs by chromatographic methods revealed that 52.9% were contaminated by AFs. AFB1 was the principal component in all AF-contaminated samples, with a mean level of 14.0, and 1.08 µg/kg in peanut and cashew nut, respectively. Eleven samples (32.4%) exceeded the total AF maximum level (4 μg/kg) and 8 samples (23.5%) exceeded the AFB1 (2 μg/kg) established by the European Commission. Our findings suggest that the incidence of AFs emphasizes the need for regular monitoring and a more stringent food safety system to control AFs at the lowest possible levels... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aflatoxin; Peanut; Cashew nut; Fungi; Risk assessment. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502019000100502 |
| |
|
|
| Machado,Simone Caetani; Landin-Silva,Mariane; Maia,Patrícia Penido; Rath,Susanne; Martins,Isarita. |
| The development of a QuEChERS-HPLC-DAD method using a Lichrospher 60 RP-Select B column (250 x 4.6 mm x 5 µm) at 40ºC, mobile phase constituted by phosphate buffer:acetonitrile (75:25, v/v) at a initial flow rate of 0.5 mL min-1, increased by 1.2 mL min-1 and at 265 nm is presented for simultaneous determination of sulphadiazine, sulphametoxipiridazine and sulphamethoxazole in chicken breast samples. QuEchERS is inexpensive, fast and easy, and the extraction of the analytes of the matrix was successfully employed. In addition, the method presented linearity, in the range of 25, 50, 100, 150, 175, and 200 µg kg-1, precision, selectivity and sensitivity. The intraday precision (RSD %) for QuEChERS method was between 3.6-10.8 (SDZ), 6.9-14.1 (SPZ) and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: QuEChERS; Sulphonamides determination; Veterinary drugs residues; Chicken breast; HPLC-DAD. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502013000100017 |
| |
|
|
| Sanson,Ananda Lima; Silva,Suéllen Cristina Rennó; Martins,Matheus Coutinho Gonçalves; Giusti-Paiva,Alexandre; Maia,Patrícia Penido; Martins,Isarita. |
| A liquid-liquid extraction (LLE) combined with high-performance liquid chromatography-diode array detection method for simultaneous analysis of four chemically and structurally different antineoplastic drugs (cyclophosphamide, doxorubicin, 5-fluorouracil and ifosfamide) was developed. The assay was performed by isocratic elution, with a C18 column (5 µm, 250 x 4.6 mm) and mobile phase constituted by water pH 4.0- acetonitrile-methanol (68:19:13, v/v/v), which allowed satisfactory separation of the compounds of interest. LLE, with ethyl acetate, was used for sample clean-up with recoveries ranging from 60 to 98%. The linear ranges were from 0.5 to 100 µg mL-1, for doxorubicin and 1 to 100 µg mL-1, for the other compounds. The relative standard deviations... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antineoplastic drugs/simultaneous determination in plasma; Liquid-liquid extraction; High-performance liquid chromatography/diode array detector. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502011000200017 |
| |
|
|
| Alezandro,Marcela Roquim; Almeida,Sandra Aparecida de; Maia,Patrícia Penido; Carvalho,Helenice Aparecida de; Azevedo,Luciana; Vieira,Elisabeth Pizzamiglio. |
| Este trabalho teve por objetivo determinar a composição centesimal e o conteúdo de Daidzeína (D) e Genisteína (G) da cultivar BRS 243 RR por CLAE. O preparo da amostra para cromatografia envolveu a remoção da gordura com hexano . Os analitos foram extraídos com etanol 70% acrescido de 0,1% de ácido acético. As condições cromatográficas otimizadas foram: coluna C18, fase móvel metanol: ácido acético 5% (1:1 v/v), vazão 0,5 mL/minuto, temperatura da coluna 30 °C, volume de injeção 40 µL e leitura em 254 nm. Os parâmetros de validação avaliados foram: linearidade y = 11242 x -37433, r = 0,9976 (D) e y = 18510 x -66761, r = 0,9980 (G); coeficientes de variação dos estudos de precisão intradia CV = 5,3% (D), CV = 6,7% (G) e interdias CV = 8,7% (D), CV = 9,7%... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soja transgênica; Isoflavonas; Daidzeína; Genisteína; Composição centesimal; CLAE. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612008000300003 |
| |
|
|
|
