PROGRAM AND PLANS: New Custom Analysis Schedule (172) for Blanks In Reply Refer To: January 3, 1994 Mail Stop 412 OFFICE OF WATER QUALITY TECHNICAL MEMORANDUM NO. 94.06 Subject: PROGRAM AND PLANS: New Custom Analysis Schedule (172) for Blanks PURPOSE OF THIS MEMORANDUM A new custom analysis schedule -- Schedule 172 -- is now available at the National Water Quality Laboratory (NWQL) to produce quality control (QC) data to support the new protocol for low level inorganic analyses. This memorandum describes (1) the types of blank samples covered by Schedule 172, (2) analyses covered by the schedule, (3) cost and sample turnaround time, (4) sample tracking, (5) reporting results, and (6) supplies. SAMPLES COVERED Schedule 172 was developed to provide QC data on appropriately preserved deionized water field sampling and processing blanks and for blanks used to monitor possible contamination in preservatives and other supplies. The objective is to provide very low-level data so project personnel can identify (and subsequently remove) contamination arising from equipment, supplies, field methods, and field conditions. Samples can include (1) equipment or supply blanks, (2) field blanks, and (3) samples from deionizing units in Field Service Units. Blanks analyzed for major cations and trace metals must be preserved with ultrapure nitric acid. Blanks for nutrients must be preserved with mercuric chloride. Schedule 172 is not suitable for the analysis of environmental water matrices. Therefore, you can not use this schedule for the analysis of environmental samples. ANALYSES COVERED Schedule 172 has been developed specifically for analyzing sample blanks for major cations, trace elements, and nutrients at low concentration levels. Major cations will be determined by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Results will be reported to the method detection limits (MDLs). Therefore, the concentrations reported will be lower than those from the current ICP-OES method. Trace elements will be determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Results will be reported to the MDLs, which are lower than those from the current ICP-MS method (see Methods of Analysis by the U.S. Geological Survey National Water Quality Laboratory - Determination of Metals in Water by Inductively Coupled Plasma-Mass Spectrometry, Lynda M. Faires, U.S. Geological Survey, Open-File Report 92-634). Nutrients will be determined by low-level automated-segmented flow (ASF), and results will be given following the usual method reporting criteria (MDLs). Schedule 172 analytes and the MDLs are tabulated in Table 1. ANALYSIS COST AND SAMPLE TURNAROUND TIME The cost of Schedule 172 will be $225 per sample. The turnaround time will be 2 weeks from sample login at the NWQL to the time at which the data are available for retrieval. Blank samples to be determined under Schedule 172 will be analyzed on Thursday and/or Friday each week. This will improve analysis efficiency, ensure quick sample turn-around times, and improve sample tracking. With this analysis schedule in mind, you can better coordinate sample shipment. SAMPLE TRACKING Field personnel must submit the Analytical Services Request (ASR) form with the following statement in the comment field "Attn. Ed Zayhowski - FIELD COLLECTION & PROCESSING BLANKS, LOW LEVEL ANALYSES". We recommend that appropriate codes be used for storing the QC data in NWIS-I (see Branch of Quality Assurance Memos 90.03 and 92.01). These include a sample medium code (for example Q), sample type (2 for blanks), and the 99100 and 99101 codes to identify the type and source of the blank water. REPORTING OF RESULTS The analytical results from Schedule 172 will be available through conventional means (NWIS-I). The data will be assigned new method characters with specific significant figures that in-turn will ensure the standard rounding routines are not used. Results that are less than the MDLs will be reported as '<' the MDL value. The data results from Schedule 172 may be stored in your local NWIS-I database. However, the data must NOT be released to WATSTORE because the methods are not approved. This means that the NWIS-I option to "FLAG APPROVED SAMPLES" must be used to flag these samples with a "Z" (local-Use Data) in the data base. SUPPLIES* All supplies can be obtained from the Ocala Quality Water Service Unit (QWSU). These supplies and costs are: Item Quantity Cost ________________________________________________________ Preservatives Ultrex nitric acid in borosilicate ampules for major cations/trace elements box of 24 $125.00 Ultrex nitric acid in Teflon vials for major cations/trace elements each 20.00 Mercuric chloride ampules for nutrients box of 24 42.00 Bottles Acid rinsed, 250 mL, natural (clear) polyethylene bottles and caps for major cations/ box of 15 6.00 trace elements box of 225 85.00 125 mL, amber, polyethylene box of 100 16.00 bottles for nutrients box of 660 62.00 _________________________________________________________ * NO other preservatives or bottles can be substituted. Initially, borosilicate glass ampules of Ultrex nitric acid will be available for the low-level protocol. During a series of tests at the NWQL, the current lot of these ampules has been found to contain measurable levels of aluminum, barium, boron, calcium, chromium, magnesium, silica, and sodium. Similar results were found for ampules of three other types of glass. Furthermore, based on an industry survey, it appears likely that these contaminants will always be present at some level whenever glass ampules are used to hold the acid. To assist District personnel in the quantification of contaminants, all acid preservatives for the low-level protocol will be shipped with a certificate of analysis indicating the measured levels of each element in selected ampules from each ordered lot. The certificate will assist in interpretation of blank and environmental data, and should help reduce the occurrence of false positives. While the measured levels of contamination from the ampules are low, the observed concentrations will cause some false positives in environmental data. Therefore, Teflon vials of Ultrex nitric acid will be made available (probably beginning in March) for projects that require or wish to use a contaminant-free acid preservative. A certificate of analysis will also be shipped with the vials. However, initial tests show that the concentration of each analyte is below the MDL. The Teflon vials are expected to cost approximately $20.00 per vial, with a $4.00 refundable deposit that will be reimbursed upon return of the vial. A mechanism for returning vials will be developed by the Ocala QWSU. The Office of Water Quality (OWQ) will work with the NWQL and the Ocala QWSU to streamline the process for obtaining and returning the vials. We will also seek ways to reduce the cost. Please contact Kathy Fitzgerald, OWQ, concerning questions about whether to use ampules or vials on individual projects. REMINDERS 1. Schedule 172 is ONLY available for the analysis of deionized water blanks. 2. Results from Schedule 172 are NOT to be entered into the WATSTORE system. David A. Rickert Chief, Office of Water Quality Attachment not included: Sample ASR Form This memorandum does not supersede any previous Office of Water Quality Technical Memorandum. Key Words: Analytical schedule, blanks, contamination, trace elements Distribution: A, B, S, FO, PO, AH Table 1. Method Detection Limits for Schedule 172* _________________________________ ICP-OES Analyte MDL, mg/L B 0.002 Ca 0.002 Fe 0.003 Mg 0.001 Na 0.025 SiO2 0.02 _________________________________ _________________________________ ICP-MS Analyte MDL, ug/L Ag 0.2 Al 0.3 Ba 0.2 Be 0.2 Cd 0.3 Co 0.2 Cr 0.2 Cu 0.2 Mn 0.1 Mo 0.2 Ni 0.5 Pb 0.3 Sb 0.2 Sr 0.1 Tl 0.1 U 0.2 Zn 0.5 __________________________________ __________________________________ ASF Analyte MDL, mg/L Ammonia (N) 0.002 Nitrite (N) 0.001 Nitrite + Nitrate (N) 0.005 Phosphate (P) 0.001 __________________________________ *The MDL is the concentration that can be reported at the 99% confidence level. It is calculated from the measured analytical precision at an analyte concentration 1 to 5 times the estimated instrument detection limit following the procedure outlined in the Code of Federal Regulation 40 CFR 136 Appendix B, p. 537-539.