Native vs photoinduced chemiluminescence in dimethoate determination

Catalá-Icardo, Mónica; López-Paz, José Luis; Choves-Barón, C.; Peña-Bádena, A.

doi:10.1016/j.aca.2011.10.043

Cited by 10 publications

(13 citation statements)

References 23 publications

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“…Previous studies carried out in our laboratory [13] showed that 20% ACN did not affect the CL detection of dimethoate, while methanol and ethanol inhibit light emission. Therefore, ACN:water was selected as the mobile phase.…”

Section: Optimization Of Hplc Systemmentioning

confidence: 99%

“…The authors have previously published a flow injection analysis (FIA) -CL method for the determination of dimethoate in water samples [13]. The method developed was highly sensitive and, in general, good results were obtained.…”

Section: Introductionmentioning

confidence: 99%

“…A preliminary study was performed using concentrations similar to those found for the FIA-CL determination of dimethoate [13]. A concentration of 3 mg/L of the pesticides was employed in this study.…”

Section: Optimization Of the CL Systemmentioning

confidence: 99%

“…In fact, CL has been gaining increasing acceptance and has been used to determine OPPs residues in recent years [9][10][11][12][13][14][15]. Nevertheless, practical application of the HPLC-CL technique for the determination of pesticides is still uncommon.…”

Section: Introductionmentioning

confidence: 99%

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Determination of organothiophosphorus pesticides in water by liquid chromatography and post-column chemiluminescence with cerium(IV)

Catalá-Icardo

Zamora

Torres-Cartas

et al. 2014

Journal of Chromatography A

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A new, fast, selective and sensitive method has been developed for the simultaneous determination of nine organothiophosphorus (OTP) pesticides, namely omethoate, dimethoate, disulfoton-sulfoxide, methidathion, phosmet, malathion, diazinon, pirimiphos-methyl and chlorpyrifos. The pesticides were separated on a Kinetex C18 column by gradient elution with acetonitrile:water. A post-column basic hydrolysis of the pesticides and later a chemiluminescence (CL) reaction with cerium (IV) in acid medium was carried out. Hexadecylpyridinium chloride highly enhanced the CL emission. Under optimized conditions, linearity, precision, limits of detection and quantification, and accuracy were determined. Both selectivity and sensitivity were compared with those obtained with UV detection. In combination with SPE, limits of detection in the range 15-80 ng/L and 5-30 ng/L were obtained when 250 mL and 1000 mL of solution were treated, respectively. When applied to 250 mL of sample the inter-day precision of the method was between 3.5% and 7.3% and the intra-day precision between 2.9% and 6.0%. The method was applied to determine OTP pesticides in spiked water samples from different origins: irrigation, river, sea, ground, spring, mineral and tap waters, being the percentage of recovery of added amounts near 100% form most of the pesticides.

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Section: Optimization Of Hplc Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Optimization Of the CL Systemmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Determination of organothiophosphorus pesticides in water by liquid chromatography and post-column chemiluminescence with cerium(IV)

Catalá-Icardo

Zamora

Torres-Cartas

et al. 2014

Journal of Chromatography A

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“…Dimethoate (O,O-dimethyl-S-methylcarbamoyl methylphosphorothioate) (DMT) is widely used as an insecticide on crops (e.g., wheat, alfalfa, corn, and cotton), orchards, and vegetables; in forestry; and for residential purposes (Pappas and Kyriakidis, 2003;USEPA, 2011;Catalá-Icardo et al, 2012). Its moderate persistence coupled with its frequent applications can result in chronic surface water contamination.…”

Section: Introductionmentioning

confidence: 99%

Kinetics and mechanism of dimethoate chlorination during drinking water treatment

et al. 2014

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h i g h l i g h t sThe reaction of DMT with chlorine was of first-order in each reactant. The observed rate constant of DMT degradation was strongly pH dependent. Both bromide and humic acid promoted but ammonium inhibited the degradation of DMT. Three organic byproducts were detected in DMT degradation by chlorine. The toxicity of DMT solution obviously increased after chlorination. a r t i c l e i n f o a b s t r a c t Dimethoate (DMT), a commonly used organophosphorus pesticide, is of great concern because of its toxicity and potentially harmful effects on water sources. The elimination of DMT as well as the toxicity and persistence of the byproducts formed during DMT degradation is most important for the safety of drinking water. This study first determined the reaction kinetics of DMT with free chlorine (FC) under typical water treatment conditions. The reaction between DMT and FC proceeded rapidly, exhibiting first-order with respect to each reactant. The degradation of DMT by FC was highly pH dependent, and the pseudofirst-order rate constant decreased obviously from 0.13 to 0.02 s À1 with an increase in pH from 7.0 to 8.3. Bromide ion accelerated the reaction by acting as a catalyst, and the accelerated reaction rate was linearly proportional to the bromide concentration. As a ubiquitous component in natural waters, humic acid also increased the reaction rate. However, the presence of ammonium inhibited the degradation of DMT due to its rapid converting FC to chloramines. Omethoate (OMT) was identified as an important byproduct of DMT chlorination, but only accounted for ca. 28% of the DMT degraded; and other two organic byproducts were also identified. The acute toxicity of DMT solution increased after treatment with FC due to the formation of more toxic byproducts (e.g. OMT).

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