A high-performance liquid chromatographic method for the determination of cypermethrin in vegetables and its application to kinetic studies after greenhouse treatment

Metwally, Mohammed El‐Sayed; Osman, Mohammed; Al-Rushaid, Riham

doi:10.1016/s0308-8146(96)00030-1

Cited by 33 publications

(28 citation statements)

References 31 publications

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“…This faster dissipation rate of chlorothalonil in cucumbers could be due partially to its higher growth rate in comparison with other vegetables that cause a fast growth dilution effect in the pesticide concentration. This effect also has been observed by other authors 8,19 who evaluated the dissipation behavior for cucumbers grown in greenhouses.…”

Section: Dissipation Resultssupporting

confidence: 85%

“…The determination of the pesticide's fate on vegetable is very important since this will greatly affect the effectiveness of sprayed pesticides on plants, the preharvest interval and the amounts of residue on vegetables at time of harvest. 8 Chlorothalonil has been determined in different matrices such as water, fresh products and vegetables [9][10][11] by different chromatographic methods. [12][13][14][15][16][17][18] Multiresidue methods such as Luke and Mills have been used for determination of chlorothalonil in fruits and vegetables.…”

Section: Introductionmentioning

confidence: 99%

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A gas chromatographic method for the determination of the fungicide chlorothalonil in tomatoes and cucumbers and its application to dissipation studies in experimental greenhouses

Kurz¹,

Gonçalves²,

Adaime³

et al. 2008

J. Braz. Chem. Soc.

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Desenvolveu-se e validou-se um novo método para avaliar os níveis de resíduo e a dissipação do fungicida clorotalonil em tomates e pepinos cultivados em estufas experimentais. Os vegetais foram submetidos a uma única pulverização com clorotalonil em meia dose, dose recomendada e dobro da dose. Os resíduos de clorotalonil foram extraídos em sistema Ultra-Turrax empregando acetato de etila na presença de sulfato de sódio anidro e determinados por cromatografia gasosa com detecção por captura de elétrons. As curvas analíticas foram lineares de 0,005 a 5,0 mg L -1 , com coeficiente de determinação maior que 0,995. Os ensaios de precisão fornecem resultados aceitáveis com valores de RSD abaixo de 10,5% e recuperações entre 92,2 e 114,5% para tomate, e entre 86,2 e 103,3% para pepino, ambos obtidos para níveis de fortificação 0,028, 0,28, 2,8 e 5,0 mg kg -1. A interpretação estatística dos níveis de resíduo indicou um modelo de primeira ordem para o comportamento da dissipação do clorotalonil. O tempo médio de meia-vida para o tratamento na dose recomendada, nos dois anos experimentais, foram 8,8 dias para tomate e 1,6 dia para pepino. A taxa mais elevada da diminuição de resíduos de clorotalonil em pepino é devida, principalmente, à taxa de crescimento mais elevada deste vegetal com relação ao tomate. O método desenvolvido provou ser eficiente para a determinação de resíduos de clorotalonil em tomate e pepino até o nível de 0,02 mg kg -1 , permitindo avaliar o risco da exposição do consumidor.A new method to evaluate the levels of residue and the dissipation of chlorothalonil fungicide in tomatoes and cucumbers grown in experimental greenhouses was developed and validated. The vegetables were submitted to a single spraying with chlorothalonil at half, equal to and double of the recommended dose. Chlorothalonil residues were extracted in Ultra-Turrax system using ethyl acetate in the presence of anhydrous sodium sulphate and determined by gas chromatography with electron capture detection. The analytical curves were linear from 0.005 to 5.0 mg L -1 , with coefficient of determination higher then 0.995. The assays provide acceptable results with RSD values below 10.5% and recoveries were between 92.2 and 114.5% for tomatoes, and between 86.2 and 103.3% for cucumbers, both obtained from spiked samples at 0.028, 0.28, 2.8 and 5.0 mg kg -1 levels. Statistical interpretation of residue levels fitted to a first-order model for the dissipation behavior of chlorothalonil. The mean half-life after treatments at the recommended dose, in the two experimental years, was 8.8 days for tomatoes and 1.6 days for cucumbers. The higher decrease rate of chlorothalonil residues in cucumbers is mainly due to the higher growth rate of this vegetable relative to tomato. The developed method has proven to be efficient for the determination of chlorothalonil residues in tomatoes and cucumbers with a limit of quantification of 0.02 mg kg -1 level, permitting to evaluate the risk of consumer exposure to these residues.

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Section: Dissipation Resultssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

A gas chromatographic method for the determination of the fungicide chlorothalonil in tomatoes and cucumbers and its application to dissipation studies in experimental greenhouses

Kurz¹,

Gonçalves²,

Adaime³

et al. 2008

J. Braz. Chem. Soc.

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“…It was characterized by a fluctuation in the degradation behavior at first and last 5 th days, mediated by a fixed period of about 10 days at which no degradation was observed. These results are in agreement with the findings of Metwally et al (1997). These researchers reported a fluctuation between 0.66, 0.7 and 0.55 ppm.…”

Section: Degradation In Tomato Fruitssupporting

confidence: 93%

“…González-Rodríguez et al (2008) calculated cypermethrin residues in vegetables and found higher concentrations of insecticide than the suggested maximum reside limit in 18 collected samples. However, Metwally et al (1997) studied the degradation pattern of cypermethrin in tomato by using HPLC and reported 0.66 ppm insecticides concentration on the first sampling, this concentration was reduced up to 0.28 ppm after 120 hours. Furthermore, Al-Eed et al (2006) conducted a study to evaluate the behavior of cypermethrin reduction in three types of water viz.…”

Section: Introductionmentioning

confidence: 99%

Patterns of natural degradation of cypermethrin in tomato fruits, water and soil under the desert environment of Ogla Oasis Cyrenaica - Libya

Amer¹,

EL-Awami²,

Elsiddig³

et al. 2015

JEBAS

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Degradation line of cypermethrin were studied in different samples of tomato fruits, water, and soil from ogla oasis in the desert environment of Cyrenaica, -Libya. The targeted insecticide was applied to the tomato crop, water, and soil of the studied area with the recommended dose. Representative samples from all three subjects were taken daily which started from the first day of treatment to the 20 th days of experimentation. Extraction and cleanup were conducted on the 20 th days and finely detection of the residues was measured by using Gas chromatography (GC-ECD) instrument. Results of the study revealed 0.06, 1.06, and 2.44 ppm insecticide concentration on the first sampling date from tomato fruits, water, and soil respectively. However after one week 33, 56 and 65% reduction in insecticide concentration was reported in tomato fruits, water and soil respectively. After 2 weeks the reduction percentage was reported 66%, 88%, and 93% chronologically, and the degradation exert 91%, 97%, and 99.1% in the same order at the last sampling date. Results concluded that the trends of cypermethrin degradation were fluctuating and slow in tomato fruits while in water and soil it appears regular. However the degradation in soil was the fastest.

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“…A total of 32.2% of the citrus samples from markets of the Valencian community (Spain) contained organo-phosphorous (OP) pesticide residues and 6.9% exceeded the European Union MRL's [21]. Metwally et al [22] used a high-performance liquid chromatographic method to study the disappearance kinetics of cypermethrin under field conditions on cucumber, eggplant, green pepper and tomato. The high disappearance rate of the pesticides on cucumber is mainly due to the high growth rate of this fruit relative to the other fruits.…”

Section: Introductionmentioning

confidence: 99%

Monitoring of pesticide residues on cucumber, tomatoes and strawberries in Gaza Governorates, Palestine

Safi¹,

Abou-Foul

El‐Nahhal

et al. 2002

Nahrung

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Three techniques of gas chromatography (GC) either with flame photometric-detector (FPD), electron capture detector (ECD), or with mass-spectrometry (MS) were applied for identification and quantification of pesticide residues on 45 samples of cucumber, tomatoes, and strawberries in fifteen locations in Gaza Governorates. GC-FPD analysis showed the presence of four different organo-phosphorus (OP) pesticides, their levels were very low and below maximum residue limits (MRL's). GC-ECD detected ten different pesticides at levels below the MRL's. Using the GC-MS technique, alpha and beta-endosulfan, chlorpyrifos, carbofuran, chlorfluazuron, triadimenol I and II, penconazole, coptafolmetabolite, pyrimethanil and iprodione were detected and confirmed on some samples of cucumber, tomatoes and strawberries. All GC-MS pesticide residues detected on tomato were below the MRL's except chlorfluazuron while on strawberry were below the MRL's except penconazole, chlorfluazuron and pyrimethanil, but on cucumber were slightly higher than the MRL's except alpha and beta-endosulfan. Also, statistical analysis of pesticide residues in all samples showed that most of the detected residues mean were significantly lower than the MRL's (p < 0.05). Generally, tomatoes showed the least number and level of pesticide residues by all the GC-techniques. On the other hand, strawberries showed greater number and levels of pesticide residues, particularly by the GC-MS technique. These results indicate that the protective period to elapse before harvesting should be increased especially on strawberry. The results also can help in risk assessment of consumers exposure to the expected pesticide residues.

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A high-performance liquid chromatographic method for the determination of cypermethrin in vegetables and its application to kinetic studies after greenhouse treatment

Cited by 33 publications

References 31 publications

A gas chromatographic method for the determination of the fungicide chlorothalonil in tomatoes and cucumbers and its application to dissipation studies in experimental greenhouses

A gas chromatographic method for the determination of the fungicide chlorothalonil in tomatoes and cucumbers and its application to dissipation studies in experimental greenhouses

Patterns of natural degradation of cypermethrin in tomato fruits, water and soil under the desert environment of Ogla Oasis Cyrenaica - Libya

Monitoring of pesticide residues on cucumber, tomatoes and strawberries in Gaza Governorates, Palestine

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