کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1200526 1493672 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Hydrodynamic radius determination with asymmetrical flow field-flow fractionation using decaying cross-flows. Part II. Experimental evaluation
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Hydrodynamic radius determination with asymmetrical flow field-flow fractionation using decaying cross-flows. Part II. Experimental evaluation
چکیده انگلیسی

In this study we investigate the effect of programmed cross-flows on the error in the hydrodynamic radii (rh) determination with asymmetrical flow field-flow fractionation (AsFlFFF). Three different standard polystyrene particles (nominal radii of 30 and 40 and 50 nm) are fractionated with exponentially and linearly decaying cross-flows with different decay rates. Hydrodynamic radii are calculated according to retention theory including steric effects. Rapid decay is expected to give rise to systematic deviations in rh determination. The error in rh was found to be small when decay rates with half-lives longer than 6 min were used, whereas steeper decays could give rise to errors as high as 16% of the particle size. The error is often explained in terms of secondary relaxation. However, comparisons show that experimental errors are significantly larger than what would be expected due to secondary relaxation, suggesting that other factors also have to be considered in order to fully understand deviations for rapidly decaying cross-flow.


► We investigate the effect of programmed cross-flows on rh determination.
► Achieved rh errors were higher than what can be explained by secondary relaxation.
► Other factors, such as the flow regulation are likely to affect the results.
► Half-lives < 3 min resulted in a steeply increasing error for exponential decays.
► Half-lives < 6 min resulted in a steeply increasing error for linear decays.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography A - Volume 1253, 31 August 2012, Pages 127–133
نویسندگان
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