32 % aqueous solution of sodium C9-C11 alkylethersulfates.A dilution of 1:20 has pH 7.6. For determination of iron in serum (1). Teepol 710 originally used by the author is no longer available. A modification of Lauber's procedure can be supplied on request. 32 % aqueous solution of sodium C9-C11 alkylethersulfates.A dilution of 1:20 has pH 7.6. For determination of iron in serum (1). Teepol 710 originally used by the author is no longer available. A modification of Lauber's procedure can be supplied on request.