Document 3JVn7xnb7p4QrB622j04DRaZE

MU i^ 5jj J v>. +.: r' DIRECTIONS FOR TEST NO. J ^ ^ L> m ^ $ SUBJECT: . .. Color of "Watsr Whit,a" Aroclorg M ETHOD:_---Comparison against A.P.HJL Scale - T$cop* 1 -' ' 'v-: ' ' ?i" ' ' I w . ' . ' \V' .{ j,. .7, /- t ->.-> v7.:.v * i' 7 . -^>vy ` , - 7 . The method It applicable to Aroclor 1254, 1260, or others haring color less than P.^A, 01 ("Water faite"), ' - V. - AP.K>AStAndattif " - -. those color standards are asId solotions of pbtassiua chlorO-platlnate and cobaltoue chloride* The unit of color Is that produced by 1 ng* of platinum par liter* tfcs ratio of cobalt to platinum may be varied if necessary to match the hue* Eocause the hue of Aroclor 1254 and 1260 seems bast matched without cobalt, this has been omitted in ths preparation described* ' v- ; Dissolve 1,245 g* of potassium chLoroplatinate (K^PtCl^) containing 0.5 g* of platinum in water with 100 ml* of concentrated hydrochloric acid, and dilute to 1 li-er with distilled water. This solution has a color of 500. Prepare standards from 10 to 100 in steps of 10 by diluting 1, 2, 3 ml, ate* of the above eolution with distilled water to 50 ml* in standard high form Messier tubes* Protect the tubes from evaporation* Refer to page 13 of "Standard Methods for the Examination of %ter and Sewage" eighth edition (1936) for details of standards containing cobalt* Published by American Public health Association, 1790 Broadway, hew York. Fill a matching Messier tube with Aroclor to a height equal to that in the standard tubes* Compare with standards by looking vertically downward through the tubes upon a white or mirrored surface placed at such an angle that light is reflected upward through the column of liquid* A color tube support (Fisher 7-065, 6 ml.) i con- venieot* ^v .7`7 . / '<y ^ Inasmuch ae the proportions of ths standard color solution In the earnparisen tubes are each as to represent an aliquot part of a liter, the readings are direct as parte per million* Colors up to 100 arc recorded to ths nearaat 5* Diract comparisons are satisfactory up to 100. Above this the sample should be diluted with Carbon tetra chloride (maximum A.P.H* color -5)# and the color obtained - to nearest 10 - by multiplying by the dilution ratio. FAB:om 1-30-45 DSW 330777 iiiisESKEiki STLCOPCB4077421