Common Terminology for Solid Phase Extraction (part 1)

Aimed Compounds: Compounds that are intended to be separated from complex sample matrices;

Matrix: The environment in which the target compound is placed. The matrix usually contains a large amount of interferents;

Interferential Compounds: Compounds that affect the analysis of a target compound or that can cause damage to an analytical instrument, usually a generic term for all compounds in the matrix other than the target compound;

Sorbent: A filler in a solid phase extraction column that selectively extracts certain compounds from a sample solution;

Capacity: The total mass of a compound (including target compounds and some interferents) that a certain mass of adsorbent can retain under certain conditions;

Selectivity: The ability of an adsorbent to treat a target compound and all other sample components differently, that is, the ability to retain the target compound while excluding other components, and high selectivity for better purification;

pH: the negative logarithm of the proton (H+) concentration in the solution. The smaller the value, the greater the concentration of protons in the solution;

pK a : the negative logarithm of the dissociation constant (K a ) of the acidic compound. The smaller the value, the stronger the dissociation property of the acidic compound. When the pH of the sample solution is equal to pK a , the undissociated compound and dissociation The concentration of the compound is equal; the analyst also commonly uses pK a to indicate the dissociation of the basic compound, but the pK a value at this time represents the negative logarithm of the dissociation constant of the basic compound conjugate acid, and the larger the value indicates The stronger the ability of the basic compound to bind protons, the stronger the basicity;

Interaction: The attraction or repulsive force between two chemicals (such as between a target compound and an adsorbent, between a target compound and a solvent molecule) in a specific chemical environment;

Non-Polar Interaction: The force between a non-polar functional group on a target compound and a non-polar sorbent. This force is better reflected in a polar solvent environment, especially in a water environment. And thus also known as hydrophobic interactions, such as the interaction between phthalate compounds and C18 in aqueous environments;