A simplified procedure for determination of clofentezine residues in fruits by liquid chromatography with UV detection

Abstract

Recebido em 7/10/03; aceito em 23/1/04; publicado na web em 17/6/04 A rapid and sensitive method is described for the determination of clofentezine residues in apple, papaya, mango and orange. The procedure is based on the extraction of the sample with a hexane:ethyl acetate mixture (1:1, v/v) and liquid chromatographic analysis using UV detection. Mean recoveries from 4 replicates of fortified fruit samples ranged from 81% to 96%, with coefficients of variation from 8.9% to 12.5%. The detection and quantification limits of the method were of 0.05 and 0.1 mg kg -1 , respectively.

HPLC analysis of glycosylated amino acids

“…Since the compounds have amide bonds, the diode array detector was preferentially used at wavelengths around 225 nm instead of refraction index detector. 17,18 Owing to the fact that some compounds analysed have the same refraction index of the mobile phase, this detector was regarded as a second choice.…”

Carbon nanotube β-cyclodextrin modified electrode as enhanced sensing platform for the determination of fungicide pyrimethanil

“…HPLC analysis (Navickiene & Ribeiro, 2004) was performed using a Shimadzu LC-20AD Prominence Liquid Chromatograph (Shimadzu, Tokyo, Japan) with a diode array detector (SPD-M20A). Separation was performed on a prepacked Nucleosil 100-5 C18, analytical column (250 mm  4.6 mm, 5 mm, MachereyeNagel, Duren, Germany) and the mobile phase consisted of methanolewater (70:30, v/v).…”

“…The accuracy of the proposed method was determined by recovery assays and by comparing the results with those obtained from a previously published HPLC method (Navickiene & Ribeiro, 2004).…”

“…The accuracy of the proposed voltammetric method was assessed by comparing the results found with those obtained using a previously-published chromatographic procedure (Navickiene and Ribeiro, 2004). Five independent measurements were carried out, for both the CV and HPLC methods.…”

“…Consequently, the residue definition for foliar and post-harvest treatment in all crop groups was defined as pyrimethanil only, for both enforcement and risk assessment (EFSA, 2011). Currently, pyrimethanil residues are most commonly monitored using gas chromatography or high performance liquid chromatography (HPLC) coupled with either selective detectors or mass spectrometry (Navickiene & Ribeiro, 2004;Gulaboski & Pereira, 2009;Vaquero-Fern andez, Sanz-Asensio, Fern andez-Zurbano, L opezAlonso, & Martínez-Soria, 2013;Y añez-Sedeño, Riu, Pingarr on, & Rius, 2010). However, these methods are in general timeconsuming, labour-intensive and not environmentally friendly.…”