کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10561018 | 969759 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
On-line generation and hydrolysis of methyl borate for the spectrophotometric determination of boron in soil and plants with azomethine-H
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
A continuous-flow system for boron determination in soils and plants with spectrophotometric detection using the azometihine-H-boron complex method was developed. In order to avoid the interferences of concomitants present in samples and to increase the sensitivity, the element was separated on-line from the matrix by methyl borate generation. For this purpose, a concentrated sulfuric acid sample solution was combined with methanol in 1:3 ratio which produce enough heating for the esterification reaction without external source. Subsequently, the methyl borate produced was stripped by the addition of a nitrogen flow and separated from the bulk solution in a gas-liquid separator to be then hydrolyzed in an ammonium-phosphate buffer solution (pH 6.8). Finally, the new bulk of phases were separated in a second gas-liquid separator and the liquid phase was combined with azomethine-H to form a boron complex for its detection at 420 nm. The effects of a number of possible interferents, both anionic and cationic were evaluated. The most severe depressions were caused by fluoride and potassium for which a concentration of 100 μg mlâ1 caused a 5% depression on the signal. A linear response was obtained between the detection limit of 0.05 μg mlâ1 (3Ï of the blank) and 50 μg mlâ1 of boron. The precision (R.S.D.%) for 10 consecutive readings of the same solution (5.0 μg mlâ1 of boron) was 2.6%. Recoveries of boron added to the samples before the extraction process were 94, 97, and 101% for soil, fruit tissue, and leaf tissue, respectively. The developed system was applied to the determination of boron in soil, fruits tissue, and leaves tissue of coffee plantations from different towns of Mérida State, Venezuela.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Talanta - Volume 68, Issue 2, 15 December 2005, Pages 374-381
Journal: Talanta - Volume 68, Issue 2, 15 December 2005, Pages 374-381
نویسندگان
Pablo Carrero, Auristela Malavé, Edyleiba Rojas, Carlos Rondón, Yaneira Petit de Peña, José Luis Burguera, Marcela Burguera,