Determination of nine acidic herbicides in water and soil by gas chromatograpy using an electron-capture detector

Ngan, Fung; Ikesaki, Thomas

doi:10.1016/s0021-9673(01)88912-3

Cited by 39 publications

(11 citation statements)

References 14 publications

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“…The recoveries are given in Table 2. The recoveries obtained for the dinoseb in water samples by the present method were compared with those of the previously reported GC-ECD method; 10 the results were found to be in good agreement with that method. ; pulse amplitude, 50 mV; concentration, 1 × 10 -7 M. Fig.…”

Section: Determination Of Dinoseb In Spiked Water Samplessupporting

confidence: 66%

“…These are HPLC with amperometric detection, 1,2 HPLC-UV [3][4][5][6][7] and GC-ECD. [8][9][10][11] However, in these methods, the separation is often complex, time consuming and involves expensive apparatus. For these reasons, there is a need to develop a method which is faster, simple and accurate for the determination of dinoseb and dinoterb in environmental samples.…”

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confidence: 99%

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Differential Pulse Adsorptive Stripping Voltammetric Determination of Dinoseb and Dinoterb at a Modified Electrode

et al. 2003

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A sensitive adsorptive stripping voltammetric method for the determination of dinitrophenolic herbicides, dinoseb (DSB) and dinoterb (DTB) at a bare carbon paste electrode (CPE) and a clay modified carbon paste electrode (CMCPE) was developed. A systematic study of various experimental conditions, such as the pH, accumulation variables and composition of a modifier on the adsorptive stripping response, were examined by using differential pulse voltammetry. A significant improvement was observed in the sensitivity by using the present method with CMCPE. When CMCPE was used, a linear response was obtained over the concentration range 2 × 10 -10 to 3 × 10 -7 M and 6 × 10 -10 to 6 × 10 -7 M with lower detection limits of 1 × 10 -10 M and 5.4 × 10 -10 M for dinoseb and dinoterb, respectively, at an accumulation time of 100 s. The interference from other herbicides and ions on the stripping signals of both compounds was also evaluated. The described method was applied to estimate of the dinoseb and dinoterb in environmental samples.

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Section: Determination Of Dinoseb In Spiked Water Samplessupporting

confidence: 66%

mentioning

confidence: 99%

Differential Pulse Adsorptive Stripping Voltammetric Determination of Dinoseb and Dinoterb at a Modified Electrode

et al. 2003

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“…Alkylation with diazomethane was accomplished according to the procedure published by Ngan and Ikesaki [27].…”

Section: Diazomethanementioning

confidence: 99%

Optimized derivatization of acidic herbicides with trimethylsilyldiazomethane for GC analysis

Ranz

Korpecka

Lankmayr³

2008

J of Separation Science

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In the present study, the preparation of methyl esters of chlorophenoxy acids with trimethylsilyldiazomethane (TMSD) is reported. TMSD is a mild and safe alternative to the highly toxic, thermally labile, and explosive diazomethane. Due to the novelty of this method, the characteristics of the reaction were investigated and the derivatization procedure was screened for statistically significant factors. The parameters identified as influential are the amount of methanol as well as reaction time and temperature. A careful optimization by a complete factorial response surface design was carried out to generate optimal reaction conditions with respect to maximum recovery and reaction yield. Special emphasis has been given to an accurate validation of the derivatization procedure. LODs were determined between 4.1 and 8.1 ng/mL for the enriched sample and linearity was proofed for more than five orders of magnitude. The applicability of the method was demonstrated by the analyses of quality control material including sample preparation with SPE. Polar herbicides investigated in the study belong to acetic acid (2,4-D, MCPA, and 2,4,5-T), butanoic acid (MCPB), and propanoic acid (mecoprop). An efficient, fast, and high-throughput method for the determination of polar herbicides including the potential for automation is proposed.

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“…One of the most often used derivatising reagents in GC analysis of acidic herbicides is diazomethane, with which the derivatisation yield can reach 100% [44]. In the process the active hydrogen of the herbicide is replaced by a methyl group (Fig.…”

Section: Diazomethanementioning

confidence: 99%

“…Ngan and Ikesaki [44] developed a method of determination of acidic herbicides (dicamba, MCPA, dichlorprop, mecoprop, 2,4-D, fenoprop, 2,4,5-T, dinoseb, 2,4-DB) in water and soil aimed at analysing large numbers of samples. It is based on the earlier procedure of methyl ester formation; modification was aimed at shortening analysis time, improving safety, and making analysis simpler.…”

Section: Diazomethanementioning

confidence: 99%

Derivatisation in gas chromatographic determination of acidic herbicides in aqueous environmental samples

Rompa

Kremer

Zygmunt

2003

Analytical and Bioanalytical Chemistry

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This paper reviews derivatisation processes applied in chromatographic determination of acidic herbicides (with carboxyl and phenol groups), mainly in aqueous environmental samples. The discussion focuses on the basic derivatisation reactions used to convert herbicides to derivatives to make them analysable by gas chromatography, and possibly to reduce detection limits and/or increase extraction recovery from aqueous samples. The reactions are transesterification, esterification, silylation, alkylation, and extractive and pyrolytic alkylation. The reagents used to conduct the reactions are numerous. Diazomethane is a very efficient methylation reagent but explosive and toxic. Methyl iodide also ensures rapid and efficient methylation. Benzyl bromide can be used directly in water but derivatisation yield is low and reproducibility is poor. Butyl chloroformate and dimethyl sulfite can also be used for derivatisation in water, and acetic anhydride can be used for in-situ derivatisation of phenolic herbicides. For increasing selectivity of GC detection pentafluorobenzyl bromide (for ECD) and (2-cyanethyl)dimethyl(diethylamino)silane (for NPD) have been applied. Very characteristic ions are produced in mass spectra if silyl groups are introduced, e.g. by using bis(trimethylsilyl)trifluoroacetamide. Tetramethylammonium, trimethylphenylammonium, tetraalkylammonium, and trimethylsulfonium hydroxides and salts can by used for derivatisation at elevated temperature in the GC injection port. Extractive alkylation is relatively efficient if tetraalkylammonium salts with long chain alkyl groups are used.

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Determination of nine acidic herbicides in water and soil by gas chromatograpy using an electron-capture detector

Cited by 39 publications

References 14 publications

Differential Pulse Adsorptive Stripping Voltammetric Determination of Dinoseb and Dinoterb at a Modified Electrode

Differential Pulse Adsorptive Stripping Voltammetric Determination of Dinoseb and Dinoterb at a Modified Electrode

Optimized derivatization of acidic herbicides with trimethylsilyldiazomethane for GC analysis

Derivatisation in gas chromatographic determination of acidic herbicides in aqueous environmental samples

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