NWQL Policy Changes To: "E - All WRD Employees" cc: "Marcia A Herring, Secretary (Stenography), Denver, CO" , "Edward J Zayhowski, Supervisory Physical Sci Tech, Denver, CO" , "Merle W Shockey, Inorganic Program Chief, Denver, CO" Subject: NWQL Policy Changes Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 08 May 1996 16:57:33 -0600 From: "Peter F Rogerson, Chief, BAS, NWQL, Denver, CO" As a result of National Water Quality Laboratory (NWQL) Technical Memorandum 96.04--Inductively Coupled Plasma-Atomic Emission Spectrometry to replace Flame Atomic Absorption Spectrophotometry for the determination of dissolved trace metals and major ions in filtered acidified water samples and the effects of this change--dated March 20, 1996, the following policy changes have been implemented in the NWQL's Inorganics Program: 1. The trace metals and major ions listed in Table 1 ("custom only" column) are no longer offered on a routine basis by Flame Atomic Absorption Spectrophotometry (FAAS). They will be offered only on a custom basis. The "custom only" lab codes are now replaced by the "preferred" lab codes. Contact Merle Shockey for more information regarding custom costs for the trace metals and major ions listed in the "custom only" column in Table 1. 2. "Swapping" away from Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) no longer occurs. The ICP previously limited the specific conductance to 6,000 microsiemens per centimeter (µS/cm). A threefold dilution was required for samples with a specific conductance from 2,000 to 6,000 µS/cm. As a result of the threefold dilution, the minimum reporting limits (MRLs) were increased by a factor of three. Samples that exceed 6,000 µS/cm will also be diluted to achieve a specific conductance of 2,000 µS/cm or less. The MRL will reflect the magnitude of any dilution applied. All efforts will be made to apply the minimum dilution factor when the specific conductance exceeds 2,000 µS/cm. For more information regarding the history of "swapping" and the rationale for elimination, see NWQL Technical Memorandum 95.09--Discontinuation of Automatic Swapping--dated August 25, 1995. Table 1.- New preferred lab codes for selected trace metals and major ions [FAAS, Flame Atomic Absorption Spectrophotometry; ICP, Inductively Coupled Plasma; LC, lab code; ID, identification number] _____________________________________________________________________________ TRACE METAL CUSTOM ONLY PREFERRED OR MAJOR ION FAAS ICP LC TEST ID LC TEST ID _________________ ________________ Barium, filtered 7 01005B 641 01005C Beryllium, filtered 170 01010A 655 01010B Cadmium, filtered 126 01025A 673 01025D Calcium, filtered 12 00915C 659 00915D Cobalt, filtered 148 01035A 644 01035C Copper, filtered 151 01040A 657 01040C Iron, filtered 172 01046C 645 01046D Lead, filtered 191 01049A 646 01049C Lithium, filtered 39 01130A 664 01130B Magnesium, filtered 40 00925B 663 00925C Manganese, filtered 42 01056A 648 01056C Nickel, filtered 197 01065A 721 01065E Sodium, filtered 59 00930B 675 00930C Strontium, filtered 62 01080A 652 01080B Zinc, filtered 67 01090A 671 01090B _____________________________________________________________________________ Customers will be contacted if they request any of the lab codes in the "custom" column without previous authorization.