Tin(II) stock standard solution of 1000 gml
−1 was prepared
by dissolving 190.0mg of SnCl2·2H2O in ca. 10ml of concen-
trated HCl, adding 5ml of 0.1Mhydrazine chloride and diluting
to the mark in 100ml volumetric flask with water. This solution
was prepared daily and was stable during the day. Solutions
of 2.5% (v/v) Triton X-100 and 0.02M AOT were prepared in
water. A 0.1% (m/v) stock solution of PAN was prepared in
ethanol.