Comparison Between Three Chromatographic (GC-ECD, GC-PFPD and GC-ITD-MS) Methods and a UV-Vis Spectrophotometric Method for the Determination of Dithiocarbamates in Lettuce

• Autor(a) principal: Pizzutti,Ionara R.
• Data de Publicação: 2017
• Outros Autores: Kok,André de, Silva,Rosselei C. da, Rohers,Graciele N.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532017000500775
• topic: dithiocarbamate; fungicide; lettuce; gas chromatography; UV-Vis spectrophotometry

The purpose of this study was to compare the performance of gas chromatographic with electron capture detector, pulsed flame photometric detector and mass spectrometry (GC-ECD, GC-PFPD and GC-MS) and UV-Vis spectrophotometric methods, based on acidic hydrolysis with tin(II) chloride of dithiocarbamate and analysis of the evolved CS2. For the validation studies were assessed linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision. Recovery experiments were performed at 0.05 and 0.4 (chromatographic method) and 0.4, 0.8 and 2.0 mg CS2 kg-1 (UV-Vis spectrophotometric method). The analytical curves were linear from 0.08 to 2.0 µg CS2 mL-1 (chromatographic method) and from 0.4 to 2.2 µg mL-1 and from 2.2 to 8.9 µg CS2 mL-1 (both with r2 > 0.995) (UV-Vis spectrophotometric method). Method LODs were 0.01 and 0.28 mg CS2 kg-1 and LOQs were 0.02 and 0.4 mg CS2 kg-1 for the chromatographic and spectrophotometric methods, respectively. Acceptable accuracy was obtained for both methods (RSDs < 15.9% and recoveries from 87.7-107.4%). There was no significant difference between the techniques and detectors employees.