Extraction and on-fiber derivatization of chlorophenols in leather by internally cooled solid phase microextraction

Abstract

Neste estudo é proposto um novo procedimento analítico para a determinação de fenóis em amostras de couro utilizando a técnica de microextração em fase sólida refrigerada internamente (CF-SPME) com derivatização direta na fibra e cromatografia gasosa acoplada a espectrometria de massas com monitoramento de íons selecionados (GC-SIM-MS). As condições experimentais para a extração e derivatização foram otimizadas utilizando procedimentos quimiométricos, sendo tempo de extração e temperatura da amostra de 5 min e 170 ºC, temperatura do recobrimento da fibra de 20 ºC, e exposição da fibra ao headspace de 70 µL do agente derivatizante bis(trimetilsilil) trifluor-acetamida por 23 min. Limites de detecção variaram entre 1,03 e 2,68 µg g-1 e o desvio padrão relativo (RSD) foi menor que 15% (n = 5). Estudos de recuperações em três níveis de concentração variaram entre 64,5 e 92,3%. This study proposes a new analytical procedure based on an internally cooled solid phase microextraction technique (CF-SPME) combined with on-fiber derivatization and gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS) for the determination of phenols extracted directly from leather samples. The extraction and derivatization conditions were optimized using experimental designs, such as: extraction time and sample temperature of 5 min and 170 ºC, fiber recoat temperature of 20 ºC, and exposing the fiber to the headspace of 70 µL of bis(trimethylsylyl)trifluoro-acetamide derivatizing agent for 23 min. Detection limits ranging from 1.03 to 2.68 µg g-1 and relative standard deviation (RSD) lower than 15% (n = 5) were obtained. The recovery was studied at three concentration levels and excellent recoveries ranging from 64.5 to 92.3% were obtained.

Solvent‐free method for the determination of lignin‐derived phenols in sediments

“…Silveira et al. used the Doehlert design to determine the volume of 70 μL of derivatizing agent (BSTFA) as the most appropriate condition for the extraction of chlorophenols from leather samples by SPME, which corroborates the results obtained in this research.…”

Simultaneous determination of haloanisoles and halophenols in water using in situ acylation combined with solid‐phase microextraction with gas chromatography and mass spectrometry

“…The other is the equilibrium between headspace and polymeric fiber coating, which is related to the diffusion of the analyte from the vapor phase to the fiber coating, and the analyte interaction with the polymeric coating . The matrix‐headspace equilibrium is seen as the controlling factor at lower temperature stage, while the headspace‐coating equilibrium is more considerable at higher temperature; due that the increased temperature is advantageous to prompt the migration of analytes from liquid to vapor phase, and the use of lower SPME fiber temperature helps to increases the analyte/fiber coating partition coefficient .…”