| abstract |
Sulfonic derivatives of N-acylated covalently bound, non-crosslinked polyethyleneimine bonded phase silicas of the formula: ##STR1## is the backbone of a silica gel or controlled pore glass, n is an integer such that the polyethyleneiminopropyl silane group has an average molecular weight of from about 400 to about 1800; q is an integer of zero or one; R is selected from the group consisting of hydrogen, --(CH 2 ) x H or --(CH 2 ) m COOH where x is an integer of 1 or 2 and m is an integer of zero or 1; when R is hydrogen or --(CH 2 ) x H then R 1 is --(CH 2 ) p COOH where p is an integer of zero or 1, and when R is --(CH 2 ) m COOH then R 1 is selected from the group consisting of hydrogen or --(CH 2 ) y H where y is an integer of zero or 1, are especially useful as solid phases for the purification and separation of proteins having isoelectric points of below about 5. |