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Od/1J/P2 1d:22 Q804 p86 8428 ASCI VA.VCOLZ'ER »»» P Y SRS ®006/old <br />A S <br />Sample bottles should ba completely full, to the point of overflowing, ouch that there k no <br />eirapsea in the sample. Samples should be atorad and ahlpped In the dark at ^ tamparotura <br />of less then 4 depress eantipnda. <br />The sample size is sufficient to allow roplication of total cyanide determinations by the <br />manual method when accuracy at vary low eoncenvatlons Il.e. 0.05 mpA. or kss) Is <br />required. <br />3.1.2 Lycimeter L3 samples <br />Lycimeter samples present particular semDllnp and snelytieal problems. Lysimeters, aired In <br />unsaturated media adjacent to mine waste facilities, rarely produce sufficient water }or <br />tubttantivs and meaningful chemical anatysie ba to tlons, unless there la voluminous IeaWpO <br />from the water facility. <br />Furthermore, It is not possible to purge the lysimater to rid the it of particulate material, <br />proeipitatei or non•equitibrium fluid, as Is both normal end mandated for • monitoring wall, <br />as there is ao little sample and the lysimater would remain dry after the initial putpinp. <br />Aeeordinply, any solid partlelat in the lysimater, Including sub•0.45 mleron slays and <br />colloids, will ba entrained In the small sample volume and sett have the potential to affect <br />the cyanide analysis, (sea section 3.4 bslowl. <br />In the case of lysimater L3, the three templet collected ware 120 mlt, 20 mis and 6 mla. <br />Contaquantly, all Darticulatea lrom the tysimeterc would 6e concentrated in thaw small <br />volumes of fluid, as opposed to being flushetl from the ismDlinp ayttem and the residual <br />dispersed In one litre of fluid as would ba the ntult from normal sampllnp protocol. <br />3.2 Preservation tschniqus <br />3.2.1 Standard preservation protocol <br />In order to prevent ins eyanitla Ions ICN•I from forming hydrogen cyanide and vblatilieinp <br />from the aqueous temple and thereby altering the sample cyanide eoneentretion, the aampla <br />pH value Is kept above pH 12, where hydrogen oyanide will not ba present. Sample pH la <br />corrected to above pH 12 by using sodium or potassium hydroxides. Either of those <br />praservatlon napsnts ors normally added diraetly to the amber plats tamplinp bottle by the <br />analytical laboratory which supDllee the sampllnp bottles to the sample eollaetor. <br />Consequently, the correct amount of the preservation reagent for one Iltra of fluid la added <br />to the empty bottiec, assuming that they will be filled completely with fluid, <br />