2.4.4. Solid phase extraction of neotame
Two milliliter of filtrate was introduced in SPE cartridge previously conditioned with 3 ml methanol followed by 20 ml HPLC water. The flow rate through the cartridge was lower than 1 ml/min. The cartridge was then washed with 10 ml HPLC water to remove impurities. Neotame absorbed on the cartridge was eluted with 3 ml of methanol. The eluate was concentrated to dryness by nitrogen drying. The residue was dissolved in 1 ml of methanol and filtered through a 0.22 μm membrane filter. A 20 μl aliquot of the filtrate was injected into the HPLC.