Photolysis of imazapyr (AC 243997) herbicide in aqueous media

Mallipudi, N. Moorthy; Stout, Steven J.; Dacunha, Adrian R; Lee, An Horng

doi:10.1021/jf00002a038

Cited by 39 publications

(38 citation statements)

References 3 publications

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“…Results presented in Table 1 suggested that pH values of buffer solutions affected the photolysis rate for imazapyr and imazapic. Degradation rate of imidazolinone herbicides tested increased as pH increased, which was in agreement with previous studies [23,24,25]. This might be due to the effect of higher molar absorption coefficients at higher pH value [24].…”

Section: Results and Discussion Photolysis Of Imidazolinone Herbicidesupporting

confidence: 92%

Degradation of Imazapyr and Imazapic in Aqueous Solutions and Soil Under Direct Sunlight

Norashikin

Hussain

Hassan

et al. 2017

MJAS

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Photolytic degradation of imazapyr and imazapic in aqueous solutions (pH 3, 7 and 9) and soil under direct sunlight were studied. A total of 0.1 mL of aqueous solutions containing herbicides were collected at 0, 1, 2 and 3 days and were directly analyzed using high performance liquid chromatography equipped with ultraviolet detector (HPLC-UV) without further clean-up process. Soils that were treated with herbicides were sampled at seven different days (0, 1, 5, 10, 16, 23 and 30). The photolytic results showed that imazapyr and imazapic degraded faster in solutions compared to soils (> 90%). Photolysis of imidazolinone herbicides became more effective as the pH value increased. The half-lives for imazapyr and imazapic degradation on soil surface under sunlight were calculated at 126 days and 85.56 days, respectively. Low degradation of imazapyr and imazapic in soil becomes a concern since it may contribute to the persistency of imidazolinone herbicides in this media. The use of these herbicides should be planned well to reduce the risk of herbicides leaching into groundwater and posing risk to non-target crops and organism.Keywords: photolysis, imazapyr, imazapic, aqueous solutions, soil Abstrak Kajian degradasi fotolitik bagi imazapyr dan imazapic dalam larutan akueus (pH 3, 7 dan 9) dan tanah di bawah cahaya matahari telah dijalankan. Sebanyak 0.1 mL cecair larutan yang mengandungi racun rumpai telah diambil pada hari 0, 1, 2 dan 3 dan terus dianalisis menggunakan kromatografi cecair berprestasi tinggi dengan pengesan ultra-ungu (HPLC-UV) tanpa melalui sebarang proses pembersihan. Tanah yang telah dicampurkan dengan racun rumpai telah disampelkan pada tujuh hari yang berbeza (0, 1, 5, 10, 16, 23 dan 30). Keputusan fotolitik menunjukkan imazapyr dan imazapic lebih cepat terurai di dalam cecair berbanding dengan tanah (>90%). Fotolisis racun rumpai imidazolinon adalah lebih berkesan apabila pH meningkat. Jangka masa separuh hayat untuk imazapyr dan imazapic terurai di permukaan tanah di bawah cahaya matahari masing-masing adalah 126 dan 85.56 hari. Degradasi rendah bagi imazapyr dan imazapic dalam tanah telah menjadi suatu kebimbangan kerana ia boleh menyumbang kepada pengekalan racun rumpai imidazolinon di dalam media ini. Penggunaan racun rumpai ini perlu dirancang dengan sebaiknya bagi mengurangkan risiko untuk racun larut terlesap ke dalam air bawah tanah dan menimbulkan risiko kepada tanaman dan organisma yang bukan sasarannya.

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Section: Results and Discussion Photolysis Of Imidazolinone Herbicidesupporting

confidence: 92%

Degradation of Imazapyr and Imazapic in Aqueous Solutions and Soil Under Direct Sunlight

Norashikin

Hussain

Hassan

et al. 2017

MJAS

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“…Estudos indicam que a persistência desses herbicidas no solo é influenciada pelo pH (Loux & Reese, 1992), pela umidade (Baughman & Shaw, 1996) e pelo teor de matéria orgânica do solo (Stougaard et al, 1990). Os herbicidas do grupo químico das imidazolinonas apresentam como principais mecanismos de dissipação a degradação microbiana (Goetz et al, 1990) e a decomposição fotolítica, especialmente quando expostos à luz ultravioleta (Mallipudi et al, 1991). Tanto o imazethapyr quanto o imazapic sofrem limitada biodegradação sob condições anaeróbicas (Senseman, 2007).…”

Section: Introductionunclassified

Persistência dos herbicidas imazethapyr e clomazone em lâmina de água do arroz irrigado

Santos¹,

Marchesan

Machado

et al. 2008

Planta daninha

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RESUMO -Os herbicidas podem persistir no solo ou ser carreados para fora da área, contaminando mananciais hídricos a jusante da lavoura. Em vista disso, o presente trabalho objetivou estimar a persistência dos herbicidas imazethapyr e clomazone na lâmina de água de arroz irrigado. Para isso, foi realizado um ensaio com diferentes doses e épocas de aplicação da mistura formulada (75 g i.a. ha -1 de imazethapyr + 25 g i.a. ha -1 de imazapic) e clomazone (1.500 g i.a. ha -1 ). Para determinação dos produtos na água de irrigação, foram coletadas amostras de água a partir do primeiro dia até 62 dias após a inundação. Os resultados demonstraram que o período de detecção dos herbicidas na água de irrigação foi mais longo para o imazethapyr que para o clomazone. A meia-vida do imazethapyr na lâmina da água variou conforme o tratamento, com valores entre 1,6 e 6,2 dias, e a do clomazone foi de cinco dias.Palavras-chave: imazethapyr, clomazone, residual na água, Oryza sativa.ABSTRACT -Herbicides can persist in soil and be transported from the application site to the environment. An experiment was conducted to estimate imazethapyr and clomazone persistence in rice paddy water. The treatments included application of the formulated herbicide mixture (imazethapyr 75 g a.i. L -1 + imazapic 25 g a.i. L -1 ) and clomazone (500 g a.i. L -1 ). Imazethapyr and clomazone concentrations in water were evaluated from the 1 st to the 62 nd day after flooding. The period of herbicide detection in water was longer for imazethapyr. Imazethapyr half-life in paddy water varied between 1.6 and 6.2 days and clomazone half-life was 5 days.

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“…The main dissipation mechanisms are the microbiological degradation (Goetz et al, 1990) and the photolytic decomposition (Mallipudi et al, 1991). Imazethapyr and imazapic undergoes limited biodegradation in anaerobic conditions (Senseman, 2007;Santos et al 2008).…”

Section: Characterization Of the Physico-chemical Properties Of The Hmentioning

confidence: 99%

Herbicides Persistence in Rice Paddy Water in Southern Brazil

Zanella¹,

Adaime²,

Peixoto³

et al. 2011

Herbicides - Mechanisms and Mode of Action

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Photolysis of imazapyr (AC 243997) herbicide in aqueous media

Cited by 39 publications

References 3 publications

Degradation of Imazapyr and Imazapic in Aqueous Solutions and Soil Under Direct Sunlight

Degradation of Imazapyr and Imazapic in Aqueous Solutions and Soil Under Direct Sunlight

Persistência dos herbicidas imazethapyr e clomazone em lâmina de água do arroz irrigado

Herbicides Persistence in Rice Paddy Water in Southern Brazil

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