PDF Publication Title:
Text from PDF Page: 075
water, 1 1 hydrochlonc aCId, tap water and fmally deIOnIzed dIstIlled water m that order NOTE 1: ChromIc aCId may be useful to remove orgamc deposIts from glassware, however, the analyst should be cautIOned that the glassware must be thoroughly rmsed WIth water to remove the last traces of chromIUm ThIS IS espeCIally Important If chromIUm IS to be mcluded m the analytical scheme A commercial product- NOCHROMIX-available from Godax Laboratones, 6 Vanck St New York, NY 10013, may be used m place of chromic aCid [Chromic aCId should not be used With plastic bottles ] NOTE 2 If It can be documented through an active analytical quahty control program usmg spiked samples, reagent and sample blanks, that certam steps m the cleamng procedure are not reqUIred for routme samples, those steps may be ehmmated from the procedure Before collection ofthe sample a deCISion must be made as to the type ofdata deSired, Ie, dissolved, suspended, total or total recoverable For contatner preference, maximum holdmg time and sample preservation at time of collectIOn see Table 1 m the front part of thiSmanual Dnnkmgwatersamplescontammgsuspendedandsetteablematenalshould be prepared usmg the total recoverable metal procedure (sectIOn 4 1 4) 4 1 1 For the determmatIOn of dissolved constituents the sample must be filtered through a 045 u membrane filter as soon as practical after collectIOn (Glass or plastiC filtenng apparatus usmg plam, non-gnd marked, membrane filters are recommended to aVOId possible contammatIOn) Use the first 50-100 nil to nnse the filter flask Discard thiS portion and collect the reqUIred volume of filtrate ACidify the filtrate With 1 1 redistilled HN03 to a pH of <2 Normally, 3 nil of (1 1) aCid per hter should be sufficIent to preserve the sample (See Note 3) If hexavalent chromIUm IS to be mcluded In the analytical scheme, a portion of the filtrate should be transferred before aCidificatIOn to a separate contamer and analyzed as soon as possible usmg Method 218 4 Analyses performed on a sample so treated shall be reported as "dissolved" concentratIOns NOTE 3 If a precipitate IS formed upon aCidification, the filtrate should be digested usmg 4 1 3 Also, It has been suggested (InternatIOnal BIOlogICal Program, SympOSIUm onAnalyticalMethods,Amsterdam,Oct 1966)thatadditionalaCid,asmuchas25mlof conc HClIhter, may be reqUIred to stabilize certam types of highly buffered samples IT they are to be stored for any length of time Therefore, special precautions should be observed for preservation and storage of unusual samples mtended for metal analySIS 4 1 2 For the deternunatIOn ofsuspended metals a representative volume ofunpreserved sample must be filtered through a 0 45 u membrane filter When conSiderable suspended matenalls present, as httle as 100 ml of a well mixed sample IS filtered Record the volume filtered and transfer the membrane filter contammg the msoluble matenal to ~250 nil Gnffin beaker and add 3 ml conc redistilled HN03 Cover the beaker With a watch glass and heat gently The warm aCid Will soon dissolve the membrane Increase the temperature of the hot plate and digest the matenal When the aCid has nearly evaporated, cool the beaker and watch glass and add another 3 ml of conc redistilled HN03 Cover and contmue heatmg until MET ALS-SPDF Image | Methods for Chemical Analysis of Water and Wastes
PDF Search Title:
Methods for Chemical Analysis of Water and WastesOriginal File Name Searched:
epa600_4_79_020.pdfDIY PDF Search: Google It | Yahoo | Bing
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
Heat Pumps CO2 ORC Heat Pump System Platform More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)