Source:http://linkedlifedata.com/resource/pubmed/id/14518759
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1-2
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| pubmed:dateCreated |
2003-10-1
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| pubmed:abstractText |
This study describes the thermal pretreatment of a silica gel between 150 and 800 degrees C before derivatization with dimethyloctadecylchlorosilane as a means of reducing residual silanol activity in HPLC bonded stationary phases. A time study was done from 12 to 48 h to find the optimum time needed for dehydroxylation. With increasing pretreatment temperatures, the number of reactive silanols is reduced from 8 micromol/m2 to essentially zero at 1000 degrees C (where sintering occurs). The effects of the thermal pretreatments were observed with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and solid state cross polarization magic angle spinning (CP-MAS) 29Si NMR. Following derivatization, residual silanol activity and pH stability were tested by packing columns with the derivatized silica and carrying out a series of reversed-phase liquid chromatography (RPLC) experiments. Residual silanol activity was greatly reduced when the silica was pretreated at 800 degrees C, leading to less peak tailing for basic solutes. In a strongly basic mobile phase (pH 11.5) the pretreated silica was surprisingly stable, although bond cleavage of C18 groups from the surface was observed.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical | |
| pubmed:status |
MEDLINE
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| pubmed:month |
Sep
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| pubmed:issn |
0021-9673
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
5
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| pubmed:volume |
1011
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
23-9
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| pubmed:dateRevised |
2009-1-15
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| pubmed:meshHeading | |
| pubmed:year |
2003
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| pubmed:articleTitle |
Reducing residual silanol interactions in reversed-phase liquid chromatography. Thermal treatment of silica before derivatization.
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| pubmed:affiliation |
The Florida State University, Department of Chemistry and Biochemistry, Tallahassee, FL 32306-4390, USA.
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| pubmed:publicationType |
Journal Article
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