Extração por fluido supercrítico de alguns inseticidas carbamatos em amostras de batata, com determinação por HPLC/fluorescência e confirmação por HPLC/espectrometria de massas

Abstract

Recebido em 21/11/00; aceito em 8/8/01 SUPERCRITICAL FLUID EXTRACTION FOR SOME CARBAMATE INSECTICIDES IN POTATOES SAMPLES, WITH HPLC/ FLUORESCENCE DETERMINATION AND HPLC/MASS SPECTROMETRY CONFIRMATION. Six supercritical fluid extraction (SFE) methods were tested, by varying the following operational parameters: CO 2 pressure, time and temperature of extraction, type and proportion of static modifier, and Hydromatrix ® /sample rate into cell. Firstly, insecticide carbamates were extracted from spiked potatoes samples (fortification level of 0,5 mg.Kg -1 ) by using SPE procedures, and then final extracts were analyzed HPLC/fluorescence. Good performance was observed with SFE methods that operated with values of temperature and CO 2 pressure of 50 o C and 350 bar, respectively. Best efficiency was obtained when it was used acetonitrile as a modifier (3% on the cell volume), and Hydromatrix ® /sample rate of 2:1. Static time was of 1 min; total extraction time was of 35 min; dynamic extraction was performed with 15 mL of CO 2 , and it was used methanol (2 mL) for the dissolution of the final residue. In such conditions, pesticide recoveries varied from 72 to 94%, depending on the analyzed compound. In higher extraction temperatures, a rapid degradation was observed for some compounds, such as aldicarb and carbaryl; presence of their metabolites was further confirmed by HPLC-APCI/MS in positive mode. Detection limits for chromatographic analysis varied from 0,2 to 1,3 ng.

Monitoramento Dos Agrotóxicos Quinclorac E Carbofuran No Rio Camboriú, Município De Camboriu, Santa Catarina

“…Fonte: Adaptado de EPAGRI/CIRAM (2015) A biodisponibilidade e degradação microbiana, que dependem diretamente de diversas propriedades do solo como o conteúdo da matéria orgânica, tipo de solo e REA -Revista de estudos ambientais (Online) v.18, n. (LEÃO, 1997), que facilita sua hidrólise em meio básico pela presença da função éster em sua molécula (HIRATA et al, 2003), assim sua detecção em meio aquoso é facilitada (NUNES, 2002).…”

Análise de resíduos de agrotóxicos em tomates empregando dispersão da matriz em fase sólida (DMFS) e cromatografia gasosa

“…O método convencional usado para determinar resíduos de agrotóxicos em frutas e vegetais é baseado na extração com solvente, seguido por etapas de clean up. 7 Entretanto, novas técnicas de extração têm sido aplicadas com a mesma finalidade como extração em fluido supercrítico (EFS), 8 microextração em fase sólida (MEFS) [9][10][11] e extração em fase sólida (EFS). 12,13 Outra metodologia muito empregada em análise de matrizes complexas é a dispersão da matriz em fase sólida (DMFS), pois agrupa em uma única etapa a extração e o clean up dos extratos.…”

Determination of carbamates in beverages by liquid-liquid extraction with low temperature partitioning and liquid chromatography

“…Generally, analytical methods utilized for determination of carbamates in these matrices involve laborious steps, consume analysis time and require derivatization procedures, 40 which are not suitable in emergency cases related to intentional intoxications. 17 They usually include a liquid-liquid extraction (LLE), 18,28 solid-phase extraction (SPE), 19,22,[41][42][43] solid-phase microextraction (SPME), 44,45 matrix solid-phase dispersion (MSPD), [46][47][48] liquid-liquid microextraction, 49 dispersive liquid-liquid microextraction (DLLME), 50,51 temperature controlled ionic liquid dispersive liquid phase microextraction, 52 carbon nanotube reinforced hollow fiber liquid-phase microextraction 53 or supercritical fluid extraction 54 followed by gas 20,50,[55][56][57][58][59][60] or liquid chromatography. 1,19,48,49,52,53,[61][62][63][64][65][66][67][68][69][70] The low volatility and the thermolability of these compounds and ...…”