کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1210833 965421 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Determination of fatty alcohol ethoxylates by derivatization with phthalic anhydride followed by liquid chromatography with UV–vis detection
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Determination of fatty alcohol ethoxylates by derivatization with phthalic anhydride followed by liquid chromatography with UV–vis detection
چکیده انگلیسی

The esterification of fatty alcohol ethoxylates (FAEs) with phthalic anhydride in 1,4-dioxane was studied. At 110 °C and in the presence of urea, which increased the reaction rate, esterification was completed in 60 min. The reaction yield did not decrease when the sample contained up to 50% water. For the non-ethoxylated alcohols, the UV–vis response factors of the derivatives were not significantly different from each other (f = 1 for C12E0 as reference). The response factors decreased when the number of ethylene oxide units, m, increased, reaching constant values of ca. 0.40 and 0.65 for the n = 8 and 18 series, respectively, when m ≥ 3. Using a C8 column and gradient elution with acetonitrile/water plus 0.1% acetic acid, FAEs in industrial mixtures and cleaning products were characterized. At column temperatures of 25 and 35 °C, homologous series with even values of n from 8 up to 20, were resolved up to m = 14 and 18, respectively, and at 25 °C, series with consecutive even and odd values of n were resolved up to m = 7. Within the series, superior resolution of the ethoxymers with large values of m was achieved; however, the elution order was reversed for the m = 1 and 0 ethoxymers, which produced overlapping of a few peaks within the series. A simple procedure for the accurate prediction of the concentrations of all the ethoxymers in industrial samples was described. After preconcentration with C18 solid-phase extraction cartridges, FAEs were also characterized and quantified in environmental samples (river and sea water). The LODs were ca. 2 μM (S/N = 3) in the injected solutions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography A - Volume 1203, Issue 1, 29 August 2008, Pages 47–53
نویسندگان
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