09-08-2012, 09:42 AM
SOLID PHASE EXTRACTION
[attachment=30671]
INTRODUTION :
SPE is one of the sample preparation technique.
The aim of sample preparation is to provide a reproducible and homogeneous solution suitable for injection into column.
PROPERTIES OF IDEAL SAMPLE :
o It should be reasonably free from possible interferences.
o It should not damage the column.
o It should be compatible with proposed HPLC method.
o Solvent used for preparation of the sample should be compatible with mobilephase and should not significantly affect the retention and resolution of analyte.
PREPARATION OF SAMPLE:
The sample is best prepared in mobile phase but direct solution in mobile phase particularly in binary and ternary system is not possible.
Prepare the sample in more soluble solvent(methnol) and then small volume is diluted to desired concentration with MP.
The use of solvent different from MP in final dilution obscure the eluting peaks.
If the sample or any of its components are not soluble in mp,serious problems are likely to arise.
Precipitation of sample result in clogging of sample valve.
Precipitate can built up over the head of the column thus restricting the flow of MP and increase in back pressure.
Built up of precipitate can cause spurious peaks.
PRINCIPLE INVOLVED IN SPE:
Spe uses affinity of solutes dissolved/suspended in a liquid(mobile phase) for a solid through which the sample is passed (stationary phase) to separate a mixture into desired and undesired components.
If the portion retained on the stationary phase includes the desired analytes, they can then be removed from the stationary phase for collection in an additional step, in which the stationary phase is rinsed with an appropriate eluent.
If the portion retained on the stationary phase includes undesired analytes then it is discarded.
Spe isolates analytes of interest from urine,blood,water,beverages,soil,animal tissue etc.,
ADVANTAGES:
1. Complete extraction of analyte with higher recovery without formation of emulsion.
2. Less consumption of solvent, hence reduction in material cost and cost of disposal.
3. Filtration, removal of particulate matter.
4. Efficient separation of interfering substances from analytes.
5. Rapid sample preparation.
6. Convenient collection of analyte. Possibility of automation of entire process.
[attachment=30671]
INTRODUTION :
SPE is one of the sample preparation technique.
The aim of sample preparation is to provide a reproducible and homogeneous solution suitable for injection into column.
PROPERTIES OF IDEAL SAMPLE :
o It should be reasonably free from possible interferences.
o It should not damage the column.
o It should be compatible with proposed HPLC method.
o Solvent used for preparation of the sample should be compatible with mobilephase and should not significantly affect the retention and resolution of analyte.
PREPARATION OF SAMPLE:
The sample is best prepared in mobile phase but direct solution in mobile phase particularly in binary and ternary system is not possible.
Prepare the sample in more soluble solvent(methnol) and then small volume is diluted to desired concentration with MP.
The use of solvent different from MP in final dilution obscure the eluting peaks.
If the sample or any of its components are not soluble in mp,serious problems are likely to arise.
Precipitation of sample result in clogging of sample valve.
Precipitate can built up over the head of the column thus restricting the flow of MP and increase in back pressure.
Built up of precipitate can cause spurious peaks.
PRINCIPLE INVOLVED IN SPE:
Spe uses affinity of solutes dissolved/suspended in a liquid(mobile phase) for a solid through which the sample is passed (stationary phase) to separate a mixture into desired and undesired components.
If the portion retained on the stationary phase includes the desired analytes, they can then be removed from the stationary phase for collection in an additional step, in which the stationary phase is rinsed with an appropriate eluent.
If the portion retained on the stationary phase includes undesired analytes then it is discarded.
Spe isolates analytes of interest from urine,blood,water,beverages,soil,animal tissue etc.,
ADVANTAGES:
1. Complete extraction of analyte with higher recovery without formation of emulsion.
2. Less consumption of solvent, hence reduction in material cost and cost of disposal.
3. Filtration, removal of particulate matter.
4. Efficient separation of interfering substances from analytes.
5. Rapid sample preparation.
6. Convenient collection of analyte. Possibility of automation of entire process.