An alternative LC-UV procedure for the determination of prochloraz residues in fruits

Abstract

Um método alternativo, utilizando cromatografia líquida com detecção espectrofotométrica, para análise de procloraz como o produto de degradação 2,4,6-triclorofenol em manga, mamão e laranja é descrito. Acetato de etila, acetona e diclorometano foram testados para a extração de procloraz das frutas. Após a extração, procloraz foi submetido a uma reação com cloridrato de piridina para gerar o derivado 2,4,6-triclorofenol. A análise foi realizada por cromatografia líquida com detector espectrofotométrico e por cromatografia gasosa com detecção por captura de elétrons. Recuperações médias de frutas fortificadas (0,1 e 0,2 mg kg-1) variaram de 80 a 94% com coeficiente de variação entre 5,6% e 12,6% (n=8). Os limites de detecção e quantificação foram 0,05 e 0,1 mg kg-1 , respectivamente. O método alternativo foi aplicado a amostras de manga e mamão, as quais foram tratadas por imersão em solução da formulação de procloraz sob condições de laboratório. Além disso, amostras de frutas de mercados locais foram analisadas. An alternative method using liquid chromatography with UV detection for the determination of prochloraz as 2,4,6-trichlorophenol in mango, papaya and orange is described. Ethyl acetate, acetone and dichloromethane were tested for extraction of prochloraz from the fruits. After extraction the residue of prochloraz was derivatized with pyridine hydrochloride. The analysis was carried out using liquid chromatography with UV detection and gas chromatography with electron-capture detection. Average recoveries of prochloraz from spiked fruits (0.1 and 0.2 mg kg-1) ranged from 80% to 94% with relative standard deviations between 5.6% and 12.6% (n=8). Detection and quantification limits were 0.05 and 0.1 mg kg-1 , respectively. The LC-UV method was applied to mango and papaya samples submitted to dip treatment with a prochloraz formulation under laboratory conditions. In addition, fruit samples obtained from local markets were analysed.

Rapid and sensitive determination of the prochloraz residues in the cultivated mushroom, Agaricus bisporus (Lange) Imbach

“…Liu et al (2009) determined the prochloraz residue in mushrooms with SPE-HPLC and found the LOD level to be 38 mg kg À1 . 35 Polese et al (2006) determined the prochloraz residue levels in ginger, as 2,3,4-trichlorophenol, and they found that LOD and LOQ using the GC-ECD method were 100 and 200 mg kg À1 , respectively. 12 Blasco et al (2002) developed LC-MS and LC-UV methods to determine prochloraz in fruits and vegetables.…”

Determination of Pesticides in Fruit and Fruit Juices by Chromatographic Methods. An Overview

“…Many authors have reported the efficiency of extraction methods with different solvents such as ACN (22), hexane (23), dichloromethane (DCM) (24), acetone (25), petroleum ether (26), ethyl acetate (27), cyclohexane (28), toluene (29), and methanol (MeOH) (30) because these solvents play rather different roles and allow good recoveries of a wide range of pesticides. The n-hexane extraction will selectively yield the non-polar pesticides, while the DCM extraction will cover a wider polarity range, but obviously also include more matrix interferences.…”

“…The most commonly used GC detectors are element selective detectors such as the ECD (1,12,23,24,29,41,56,59,63,90,91), used for the detection of chlorinated pesticides, the nitrogen phosphorus detector (NPD) (57,62,75,80), used mostly for the detection of nitrogen containing pesticides, and the FPD (21,37,92), used for the detection of organophosphorus pesticides. Even after such extensive sample cleanup, pesticide analysis is confronted with a large variety of matrix related interferences that hamper the detection sensitivity, especially with the NPD and ECD (93).…”

Decay and Residue Dynamics of 25% Prochloraz Ec in Mandarin Orange by Simulating Postharvest Treatment at Different Storage Temperatures

“…1997; Blasco et al . 2003; Navickiene and Ribeiro 2005). These methods generally include liquid–liquid extraction, matrix solid‐phase dispersion extraction and solid‐phase microextraction.…”

“…According to plant metabolite study, prochloraz residue was defined as the sum of prochloraz and its metabolites containing the 2,4,6-TCP moiety, expressed as prochloraz (JMPR 2004). Methods for determining prochloraz residue in fruits (such as apple, peach, cherry, orange, lemon, mango and grape) and fruit juices have been reported (Lafuente and Tadeo 1985;Paoli et al 1997;Blasco et al 2003;Navickiene and Ribeiro 2005). These methods generally include liquid-liquid extraction, matrix solid-phase dispersion extraction and solid-phase microextraction.…”