Troubleshoot common SPE issues
Simply click the general SPE symptom that you are observing, then navigate the symptom details to define potential causes of your problems and receive appropriate solutions to resolve the problem.
|Improper conditioning.||Condition column according to phase: Reversed phase: use methanol, acetonitrile or isopropanol followed by solvent used for sample solution. Ion exchange: use methanol or isopropanol followed by a buffer at a pH which charges both sorbent and analyte.|
|Analytes have a greater affinity for the sample solution than for the column.||Choose a column having a greater selectivity for analytes.
Change pH of sample to increase affinity of analytes to sorbent.
Change polarity of sample to produce lower affinity for the analytes.
|Improper washing.||Wash column using appropriate wash solution.|
|Poor elution.||Increase eluent volume, increase eluent strength.
Decrease elution strength of washing solvent.
|Analytes have stronger interaction with column sorbent than with eluting solvent.||Choose a column that is less retentive for the analytes.|
|Elution volume is too low.||Increase the elution volume.|
|Elution solvent is too weak to disrupt analyte interaction with the column.||Change pH of eluting solvent to ensure greater affinity for the analytes.
Change polarity of eluting solvent to ensure greater affinity for the analytes.
|Column dries before sample added.||Re-condition column.|
|Capacity of column is exceeded.||Decrease sample volume.|
|Sample loading flow rate is too high.||Use a column with a larger amount of sorbent.
Decrease flow rate.
|Elution flow rate is too fast.||Allow elution solvent to seep into column before aspirating or forcing through column.
Apply in two separate aliquots versus a single aliquot.
|Using too strong a wash solution to remove interferences.||Reduce strength of wash solvent.|
|Elution volume is too small.||Increase volume of elution solvent.|
|Interferences are extracted at the same time as analytes.||Selectively wash interferences from column prior to elution.
Use a column which retains the analytes more than the interferences.
|Interference is due to leachables from column.||Wash column with eluting solvent prior to conditioning.|
|Excessive particulate matter in sample.||Filter or centrifuge sample.|
|Sample solution is too viscous.||Dilute sample with a weak solvent.|
|Inadequate vacuum.||Increase vacuum.|
|Sample volumes larger than extraction column capacity.||Use larger extraction column volumes.|
|Improper methodology.||Consider a different extraction mechanism sorbent, or format.|