Determination of pyrethroids in vegetables by HPLC using continuous on-line post-elution photoirradiation with fluorescence detection

The potential of online trace enrichment on a highly apolar short column in LC was evaluated for the determination of pyrethroids in river water. Twelve millilitres of water samples, modified with 8 mL ACN (ACN/water 40:60, v/v), were passed through 50 x 4.6 mm ID first separation column packed with 5 microm Hypersil Elite C18. Pesticides were preconcentrated in this column while the matrix background was eluted to waste. Separation of pesticides was performed on a 3.5 microm symmetric C18 column (250 x 4.6 mm ID) with an ACN step gradient as mobile phase and fluorescence detection was used after postcolumn derivatization by using UV light. The use of photochemically induced fluorescence for detection improved sensitivity and selectivity. Quantification limits ranged from 0.05 to 0.1 microg/L and pesticide recoveries at two concentration levels (0.1 and 0.5 microg/L) were between 93.1 and 118.6%, with RSD between 2.5 and 7.5% (n = 3) in river water samples. No matrix effect was detected.

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“…Fluorimetric detection was carried out at an excitation wavelength of 283 nm and at an emission wavelength of 330 nm for all pesticides [9].…”

Section: Enrichment and Analysis Proceduresmentioning

confidence: 99%

Online trace enrichment to determine pyrethroids in river water by HPLC with column switching and photochemical induced fluorescence detection

Galera

Martínez

Vázquez

et al. 2005

J of Separation Science

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“…The chromatographic method was previously optimised [11] in order to provide the maximum response and minimal broadening on the chromatograms. All determinations were performed by HPLC using post-elution photoirradiation with fluorescence detection.…”

Section: Hplc Proceduresmentioning

confidence: 99%

“…In each case, the different standard solutions were injected in the chromatographic system under the experimental conditions previously established [11]. Using the area values obtained for the pesticides in the injections of the five series of calibration solutions, it was checked if statistically significant differences existed among the three replicates of each series.…”

Section: Study Of Matrix Effect By Ancovamentioning

confidence: 99%

“…Generally, pyrethroid insecticides are analysed by gas chromatography (GC) [3,4,5,6] and liquid chromatography (LC) [7,8,9,10,11]. However, in several cases, another substance or substances present in the different matrices analysed affect the signal of analytes and, if this effect is not kept in mind, systematic errors (constant and/or proportional errors) will affect the results and cause bias [12].…”

Section: Introductionmentioning

confidence: 99%

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A comparative study of the correction of systematic errors in the quantitation of pyrethroids in vegetables using calibration curves prepared using standards in pure solvent

Martínez-Galera

López-López²,

Gil-García

et al. 2003

Anal Bioanal Chem

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A comparative study of two mathematical approaches was performed in order to correct systematic errors due to the presence of the unexpected interferences which appear when the quantitation of the analyte in real samples is carried out with calibration curves built using standards in pure solvent. These methods consisted in the establishment of different mathematical expressions which transform the concentration (Cs) obtained using calibration graphs built using pure solvent into the corrected concentration (C(M)) that should be obtained if the quantitation is carried out with calibration curves built using standards dissolved in blank matrix extracts. In the two approaches the correction is performed from the results of an intermediate precision study which was carried out using both calibration graphs (prepared using pure solvent and blank matrix extract). By using ANCOVA to compare the slope of both solvent-based and matrix-matched calibration graphs, matrix effect was found in the determination of deltamethrin in tomato and acrinathrin in tomato and pepper. In these cases, both approaches led to good results.

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“…They have been widely applied in controlling agricultural and sanitary pests 1 because of their excellent insecticidal activity, fast knockdown capability and relatively low mammalian toxicity, 2,3 and have been gradually taking the place of organophosphorus and carbamate pesticides. [4][5][6] However, most pyrethroid pesticides present higher toxicity to fish compared to other organisms.…”

Section: Introductionmentioning

confidence: 99%

Determination of pyrethroid pesticides in environmental samples using ionic liquid dispersive liquid-liquid microextraction

Wu¹,

Liu²,

Yang³

et al. 2012

J. Braz. Chem. Soc.

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Microextração líquido-líquido dispersiva (DLLME) utilizando líquido iônico (IL) como solvente extrator foi desenvolvida com uma nova abordagem para a determinação de quatro pesticidas piretróides em amostras ambientais de água e solo. Cromatografia líquida de alto rendimento com detector de UV (HPLC-UV) foi empregada na análise cromatográfica. Este método é rápido, fácil de operar e ambientalmente correto. O solvente clorado altamente tóxico foi substituído pelo IL hexafluorofosfato de 1-hexil-3-metilimidazólio ( [C 6 MIM][PF 6 ]), para o qual elevados valores de recuperação de extração e fatores de enriquecimento foram obtidos. Os efeitos do volume de IL, tipo e volume do solvente dispersor, adição de sal, pH e tempo de extração foram investigados e otimizados. Nas condições ideais, o método mostrou boa resposta linear com valores de coeficiente de correlação (R 2 ) no intervalo de 0,9943 a 0,9986. Desvio padrão relativo (RSD) variou de 3,9 a 10,1%. Fator de enriquecimento, limite de detecção e recuperação variaram de 260 a 319, de 0,94 a 1,97 μg L -1 e de 89 a 98%, respectivamente. Para amostras de água reais, RSD variou de 3,8 a 10,8%, e recuperação de 83 a 99%. Para análise de amostra de solo, RSD e recuperação variaram de 3,7 a 8,9% e 88 a 98%, respectivamente.Dispersive liquid-liquid microextraction (DLLME) using ionic liquid (IL) as extraction solvent was developed as a new approach for the determination of four pyrethroid pesticides in environmental water and soil samples. High-performance liquid chromatography with ultraviolet detection (HPLC-UV) was employed on chromatographic analysis. The method is rapid, easy to operate and enviromentally-friendly. The highly toxic chlorinated solvent was replaced by the IL 1-hexyl-3-methylimidazolium hexafluorophosphate ([C 6 MIM][PF 6 ]), in which high extraction recovery and enrichment factors were obtained. The effects of IL volume, type and volume of disperser solvent, salt addition, pH and extraction time were investigated and optimized. Under optimum conditions, the method showed good linear response with correlation coefficient (R 2 ) values in the range of 0.9943 to 0.9986. Relative standard deviation (RSD) varied from 3.9 to 10.1%. Enrichment factor, limit of detection and recovery ranged from 260 to 319, 0.94 to 1.97 μg L -1 and 89 to 98%, respectively. For real water samples, RSD ranged from 3.8 to 10.8%, and recovery from 83 to 99%. For soil sample analysis, RSD and recovery ranged from 3.7 to 8.9% and 88 to 98, respectively.Keywords: ionic liquid dispersive liquid-liquid microextraction, pyrethroid pesticides, HPLC-UV, environmental sample IntroductionPyrethroid pesticides are synthesized through biomimetic synthesis method based on the natural pyrethrin structure. They have been widely applied in controlling agricultural and sanitary pests 1 because of their excellent insecticidal activity, fast knockdown capability and relatively low mammalian toxicity, 2,3 and have been gradually taking the place of organophosphorus and carbamate pesticides. [4][5]...

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Determination of pyrethroids in vegetables by HPLC using continuous on-line post-elution photoirradiation with fluorescence detection

Cited by 76 publications

References 32 publications

Online trace enrichment to determine pyrethroids in river water by HPLC with column switching and photochemical induced fluorescence detection

Online trace enrichment to determine pyrethroids in river water by HPLC with column switching and photochemical induced fluorescence detection

A comparative study of the correction of systematic errors in the quantitation of pyrethroids in vegetables using calibration curves prepared using standards in pure solvent

Determination of pyrethroid pesticides in environmental samples using ionic liquid dispersive liquid-liquid microextraction

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