How to Choose the Appropriate SPE Cartridges

Two factors will be considered generally when choosing the SPE cartridges, which are the selection of adsorbents and the selection of cartridge specification. The proper adsorbents will separate the interfering materials and the target substances better and satisfy the retrieving demands at the same time. And there exists upper limits of the quality of compounds adsorbed by adsorbents. Once the quality of adsorbed compounds exceeds, the target substances will pass over the SPE  cartridge straightly instead of remaining in it.

The selection of adsorbents

Adsorbents should be selected according to the properties of target compounds and substrates. As to the examples, we can choose the adsorbents based on the principle that distinguishes target substances and the major interfering materials.

SpecificationMaximum sample sizeMinimum elution volume
50mg2.5mg125μL
100mg5mg250μL
150mg7.5mg375μL
200mg10mg500μL
500mg25mg1250μL
1000mg50mg2500μL
SubstratesTarget substancesMajor Interfering MaterialsSPE Cartridges
Soil, Sewagehydrophobic organic pollutantsHumic substancesC18, SLC
Fruits, vegetables, Chinese medicine, fruits syruppesticide residuesCarbohydrates, pigments, organic acids, phenolsNH2、Carbon/NH2
Pesticide residues with weak polarityC18
Alkaline drugsPCX
Acidic drugsPAX
GreaseLiposoluble vitamins, phospholipids, aflatoxinsfatNH2、PSA

The selection of cartridge specification

After choosing the proper adsorbent, we should choose the proper SPE cartridges with the best specification according to the volume of samples. And if the quality of the compounds to be measured is beyond the limit, the target substance will not be remained effectively, and the result of the elution is not good. Therefore, it is necessary to choose the proper specification.

SpecificationMaximum sample sizeMinimum elution volume
50mg2.5mg125μL
100mg5mg250μL
150mg7.5mg375μL
200mg10mg500μL
500mg25mg1250μL
1000mg50mg2500μL