Este trabalho descreve o analisador semi-contínuo (FORMAL-FLU) sensível e seletivo para determinação fluorimétrica de formaldeído no ar atmosférico. O método é baseado na reação entre formaldeído e Fluoral-P, produzindo o derivado fluorescente 3,5-diacetil-1,4-diidrolutidina (DDL), que quando excitado em 410 nm, emite fluorescência em 510 nm. O analisador consiste de uma câmara difusora de gase...

Simple and sensitive spectrofluorimetric method for phosphorus determination in food samples after microwave mineralisation has been described. The proposed method is based on the formation of a fluorescent chelate between morin and aluminium and the fluorescence quenching after addition of phosphates solution. Additionally, the method with quinine sulphate was modified and applied for food sam...

Hydrogen peroxide (H2O2) level in biological samples is used as an important index in various studies. Quantification of H2O2 level in tissue fractions in presence of H2O2 metabolizing enzymes may always provide an incorrect result. A modification is proposed for the spectrofluorimetric determination of H2O2 in homovanillic acid (HVA) oxidation method. The modification was included to precipita...

Activities of two principal cytosolic forms of human aldehyde dehydrogenase, ALDH1A1 and ALDH3AI in colon tumor homogenates and surrounding tissue fragments were measured, using isozymeselective, fluorimetric assays. The assays are based on two fluorogenic substrates, 6-methoxy-2-naphthaldehyde and 7-methoxy-l-naphthaldehyde, and are independent of NADH determinations. The results show high var...

A single solution protocol has been widely used for the fluorimetric determination of H2O2 in natural waters by its bleaching of the fluorescing scopoletin in the presence of the enzyme horseradish peroxidase (HRP). In this protocol, the reaction between scopoletin and H2O2 in the sample and the subsequent internal additions, and the measurements of the fluorescence are all carried out at a sin...

A derivação fotoquímica é proposta como abordagem para induzir fluorescência intensa (412/465 nm) da eritromicina. Parâmetros experimentais importantes como o tempo de irradiação com UV e tipo e concentração de ácido usado para tratar a solução de analito foram ajustadas. Limites de detecção e quantificação de 0,025e 0,085 μg mL foram obtidos com resposta linear até 200 μg mL. O procedimento é ...