A short-column technique for concentrating mutagens/carcinogens having polycyclic structures

Copper phthalocyanine trisulfonate (cpt) is known to form complexes with polycyclic planar compounds and for that reason has been used in a rayon fiber-supported form as a ligand to selectively trap polycyclics, e.g., mutagenic/carcinogenic heterocyclic amines and polycyclic hydrocarbons. With the rayon-supported cpt, batch-wise treatment is employed in the adsorption of polycyclic mutagens from samples such as an aqueous extract of food, river water, and human urine. We have now found that chitin (poly-N- acetylglucosamine) powder bearing covalently linked cpt residues is suitable for preparing a short packed column through which a sample solution may be passed. The derivatization of chitin to fix the cpt ligand on the hydroxyl groups with the use of Reactive Blue 21 proceeded more rapidly than that of the cellulose supports, and the resulting cpt-chitin showed a cpt content of 44 μmol/g, a content twofold greater than that of cpt-rayon and fourfold greater than that of cpt-cellulose prepared under equivalent conditions. A sample of cpt-chitin (0.12 g) was placed in a Sep-Pak cartridge case, and the column was tested for its utility. Compounds, mostly mutagens, having structures of three or more fused rings (aflatoxin B₁, IQ, PhIP, and six others tested) were efficiently adsorbed (>85%) to the column when their 10⁴-10^-6 M buffered solutions (5 ml, pH 7) were passed through it (flow rate, 510 ml/min). Compounds with fewer than three rings (eight compounds tested) flowed through the column with little or no adsorptions. The adsorbed compounds can be eluted with a mixture of methanol and concentrated ammonia. This technique was successfully applied for concentrating mutagenic components from Beef Extract and river water. The method is superior to the previous methods in terms of selectivity and high recovery for polycyclics. Simplicity and a less time-consuming nature of manipulation are advantageous. This technique is expected to be useful generally in studies dealing with planar polycyclic molecules.