A composition comprising a compound of formula (I) or (II): wherein r and q are independently integers of 1 to 3; R.sub.f is linear or branched chain perfluoroalkyl group having 1 to 6 carbon atoms; j is an integer 0 or 1, or a mixture thereof, x is 1 or 2, Z is --O-- or --S--, X is hydrogen or M, and M is an ammonium ion, an alkali metal ion, or an alkanolammonium ion is disclosed.