کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9748871 | 1493794 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Liquid chromatography of polymers under limiting conditions of adsorption
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کلمات کلیدی
SECTHFELSDEvaporative Light Scattering Detector - آشکارساز پراکندگی نور تبخیریUltraviolet - اشعه فرابنفشSample recovery - بازیابی نمونهTetrahydrofuran - تتراهیدروفورانMolar mass - توده مولارretention volume - حجم نگهداریBarrier methods - روش های مانعRefractive index - ضریب شکستPMMA - پلی (متیل متاکریلات) Poly (methyl methacrylate) - پلی متیل متاکریلاتPolystyrene - پلیاستایرن Size exclusion chromatography - کروماتوگرافی اندازهای طردیhigh performance liquid chromatography - کروماتوگرافی مایع با کارایی بالاHPLC - کروماتوگرافی مایعی کارا
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
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چکیده انگلیسی
The high performance liquid chromatography of polymers under limiting conditions of adsorption (LC LCA) separates macromolecules, either according to their chemical structure or physical architecture, while molar mass effect is suppressed. A polymer sample is injected into an adsorption-active column flushed with an adsorption promoting eluent. The sample solvent is a strong solvent which prevents sample adsorption. As a result, macromolecules of sample elute within the zone of their original solvent to be discriminated from other, non-adsorbing polymer species, which elute in the exclusion mode. LC LCA sample recovery has been studied in detail for poly (methyl methacrylate)s using a bare silica gel column and an eluent comprised toluene (adsorli) and tetrahydrofuran (desorli). Sample solvent was tetrahydrofuran. It was found that a large part of injected sample may be fully retained within the LC LCA columns. The amount of retained polymer increases with decreasing packing pore size and with higher sample molar masses and, likely, also with the column diameter. The extent of full retention of sample does not depend of sample volume. An additional portion of the injected desorli sample solvent (a tandem injection) does not fully eliminate full retention of the sample fraction and the reduced recovery associated with it. The injected sample is retained along the entire LC LCA column. The reduced sample recovery restricts applicability of many LC LCA systems to oligomers and to discrimination of the non-adsorbing minor macromolecular components of complex polymer mixtures from the adsorbing major component(s). The full retention of sample molecules within columns may also complicate the application of other liquid chromatographic methods, which combine entropic and enthalpic retention mechanisms for separation of macromolecules.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography A - Volume 1084, Issues 1â2, 19 August 2005, Pages 173-179
Journal: Journal of Chromatography A - Volume 1084, Issues 1â2, 19 August 2005, Pages 173-179
نویسندگان
Marián Å nauko, DuÅ¡an Berek, David Hunkeler,