کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1228035 968443 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Developing a fluorimetric sequential injection methodology to study adsorption/desorption of glyphosate on soil and sediment samples
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Developing a fluorimetric sequential injection methodology to study adsorption/desorption of glyphosate on soil and sediment samples
چکیده انگلیسی

This paper describes the development of a sequential injection method to automate the fluorimetric determination of glyphosate based on a first step of oxidation to glycine by hypochlorite at 48 °C, followed by reaction with the fluorogenic reagent o-phthaldialdehyde in presence of 2-mercaptoethanol in borate buffer (pH > 9) to produce a fluorescent 1-(2′-hydroxyethylthio)-2-N-alkylisoindole. The proposed method has a linear response for glyphosate concentrations between 0.25 and 25.0 μmol L− 1, with limits of detection and quantification of 0.08 and 0.25 μmol L− 1, respectively. The sampling rate of the method is 18 samples per hour, consuming only a fraction of reagents consumed by the chromatographic method based on the same chemistry. The method was applied to study adsorption/desorption properties in a soil and in a sediment sample. Adsorption and desorption isotherms were properly fitted by Freundlich and Langmuir equations, leading to adsorption capacities of 1384 ± 26 and 295 ± 30 mg kg− 1 for the soil and sediment samples, respectively. These values are consistent with the literature, with the larger adsorption capacity of the soil being explained by its larger content of clay minerals, while the sediment was predominantly sandy.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microchemical Journal - Volume 98, Issue 2, July 2011, Pages 260–266
نویسندگان
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