This information can be used to support holding times and/or sample preservation and storage conditions that are appropriate or necessary to meet project-specific data quality objectives. Jasper Hattink; Doi: -. Publication date: 10 Sep 2019. 10 ° C, SODIUM THIOSULFATE. However, some chemicals are identified in SW-846 as unstable or reactive over a short timeframe, and for projects where these chemicals are of particular interest, the best practice for obtaining representative measurements is to complete testing as soon as possible after samples are collected. TOTAL DISSOLVED SOLIDS. FOR WASTEWATER: NITRIC ACID (HNO3) -- CAN BE ADDED WHEN RETURNED TO LAB.
FOR 10 METALS AND LESS: 500 ML PLASTIC. ≤ 6 ° C, 2 NAOH PELLETS & 10 DROPS ZN ACETATE. SAMPLE PRESERVATION AND HOLDING TIMES. TOTAL ORGANIC CARBON. Chapter 4 suggests that the project team consider existing information and data regarding analyte stability or perform additional testing in order to determine how best to preserve sample integrity for the analytes of interest. TOTAL SUSPENDED SOLIDS. It is also important to point out that authorized states can be more stringent when designating holding times or interpreting guidance on measuring holding times. Jasper Hattink, Roger Benzing, 2019.
Short Holding Times. NAOH = Sodium Hydroxide HCL = Hydrochloric Acid H2SO4 = Sulfuric Acid BRCL = Bromine Monochloride HNO3 = Nitric Acid. FECAL COLIFORM ON SOLID. DRINKING WATER, BACTERIOLOGICAL. FOR ALL EXCEPT MERCURY: 6 MONTHS. Special Publications. EPA METHOD 625 (BNA). ≤ 6 ° C, 3 NAOH PELLETS ***. Greater than or equal to 7 days can be evaluated in the same units in which they are expressed. TOTAL KJELDAHL NITROGEN. FOR MERCURY: 28 DAYS. Additional variables can affect chemical stability that may not have been evaluated as part of a holding time study and may need to be considered during project planning. 5 ML BRCL (WITHIN 48 HOURS).
On May 27, 2020, the American Council of Independent Laboratories (ACIL) was informed that it had been successful in convincing the US EPA to revise its guidance for sample holding times. We agree that the primary purpose of establishing maximum holding times from sample collection to preparation and analysis is to minimize changes to specific, measurable properties that were representative of the material at the time it was collected. Technical Director of Chemistry. Skip Nav Destination. SAMPLE MUST BE DRIED AT THE LAB IN AN OVEN. WASTEWATER, BACTERIOLOGICAL. US EPA to Revise its Guidance for Sample Holding Times. Holding Times and Preservation for Environmental Radiochemical Samples: An Evaluation of ISO Standard Guidelines. "Holding Times and Preservation for Environmental Radiochemical Samples: An Evaluation of ISO Standard Guidelines", Environmental Radiochemical Analysis VI, Nicholas Evans. A sample collected in January is considered to have met a specified 6 month holding time if it is prepared or analyzed before the end of July. Recommended holding times in Chapters 3 and 4 of SW-846 are clearly identified as guidelines and not EPA requirements. DOI: Hardback ISBN: 978-1-78801-735-0. FOR DRINKING WATER: HOLD UP TO 7 DAYS WITHOUT NITRIC ACID (HNO3). Rock J. Vitale, CEAC.