The four steps of the SPE solid phase extraction device and the technical key

The four steps of the SPE solid phase extraction device and the technically critical SPE solid phase extraction device are the use of solid adsorbent to adsorption of the target compound in the liquid sample, separation from the substation and interference compound of the sample, and then excerption or heating desorption with a lotion To achieve the purpose of separation and concentration of target compounds (i.e., sample separation, purification and concentration), the aim is to reduce sample substation interference, improve detection sensitivity, it is used in various types of food safety testing, agricultural residue monitoring, medical and health, environmental protection, commodity inspection, tap water and chemical production laboratories.
features of the main features: solid-phase extraction device machine by transparent lysoglass production, strong corrosion resistance.
the vacuum tank its wall thickness is uniform so that can withstand -0.096Mpa or more of the high negative pressure, long-term high-pressure use does not deform.
pressure everywhere, good air tightness, strong stability.
extraction speed consistency is good, control adjustment is convenient.
multi-channel control and the connectors are resistant to corrosion.
test tube racks of these products are highly resistant to corrosion because they are made of fluorine.
the purpose of this process is to create an environment compatible with the sample solvent and remove all impurities from the column.
two solvents are usually required to accomplish the above tasks, one solvent (primary solvent) for purifying the fixed phase and the other solvent (final solvent) for establishing a suitable fixed phase environment for the sample adesthon to be properly preserved.
the amount of each active solvent is approximately 1-2 ml/100 mg fixed phase.
solvent should not be stronger than the sample solvent, if the use of too strong solvent, will reduce the recovery rate.
solvent, which is usually weaker than the sample solution, is not a problem.
it is worth noting that during and at the end of the reification process, the fixed phase cannot be dried, as this will lead to cracks in the filler bed, resulting in a low recovery rate and reproducible, and the sample has not been properly purified.
if a dry crack occurs in the resuscation step, all the resuscation steps must be repeated.
2. The sample step on the sample load sample refers to the process by which the sample is added to the solid phase extraction column and the sample solvent is forced to pass through the fixed phase, at which point the adlys and -batch sample interference remain on the fixed phase.
this step of the key market protection target sample adsorption on the fixed phase, so if you take a manual sample, as far as possible to slow down the sample speed, so as not to wear leakage.
in order to preserve the adlyte, the solvent that dissolves the sample is weak.
If the solvent is too strong, the admiss will not be retained, and the recovery rate will be very low, a phenomenon known as a leak. Use a weak sample solvent as much as possible, so that the solute can be strongly preserved or narrow spectral band.
As long as there is no leakage, a large volume of sample size (0.5-1L) is allowed. Sometimes solid samples are extracted with a strong solvent, so the extract cannot be directly sampled.
so the extract is diluted with a weak solvent to obtain a suitable total solvent strength.
For example, a soil sample, using 50% methanol extraction, to obtain 2 ml of extraction fluid, with 8 ml of water dilution, to obtain 10% methanol solution, so that you can directly on the inverse solid phase extraction column without leakage problems.
3. After the wash Wash analyt is retained, it is usually necessary to wash the fixed phase to wash off the unwanted sample parts, the wash solvent is slightly stronger than or equal to the sample solvent.
washing solvent as weak as possible to wash as many interference parts as possible, but not strong enough to wash away any one of the adlysses.
solvent volume can be 0.5-0.8 ml/100mg fixed phase.
should not use too strong solvent when washing, too strong solvent will be strong to retain impurities wash down.
use too weak solvent, will make the washing volume increased.
can be changed to strong and weak solvent mixing, but mixed or before and after the use of solvent mutual dissolution.
4. After elute the Elute wash, the adlyte is eluted from the fixed phase, and the amount of the elution solvent is generally 0.5-0.8 ml/100 mg fixed phase.
and the solvent is carefully selected, the solvent is too strong, some of the more retained unnecessary parts will be washed out;
need more lotion to wash it out