Louisiana Administrative Code › Title 48 - PUBLIC HEALTH-GENERAL › Part V - Preventive Health Services › Subpart 28 - Drinking Water Laboratories › Chapter 80 - Certification of Laboratories Performing Drinking Water Analyses › Subchapter C - Criteria and Procedures for Chemical Testing and Analysis › Section V-8061 - General Laboratory Practices

Current through Register Vol. 50, No. 6, June 20, 2024
A.
					 Chemicals/Reagents. Chemicals and reagents used must meet the specifications in
					 the referenced method. If not specified therein, then analytical reagent (AR)
					 grade or American Chemical Society (ACS) grade chemicals or better shall be
					 used for analyses in certified laboratories.
B. Reagent Water. The laboratory shall have a
					 source of reagent water having a resistance value of at least 0.5 megohms-cm
					 (conductivity less than 2.0 micromhos/cm) at 25°C. High quality water
					 meeting such specifications may be purchased from commercial suppliers. Quality
					 of reagent water is best maintained by sealing it from the atmosphere. Quality
					 checks to meet specifications above shall be made and documented at planned
					 intervals based on use. This planned interval should not exceed daily.
					 Individual analytical methods may specify additional requirements for the
					 reagent water to be used. Reagent water for organic analysis must be free from
					 interferences for the analytes being measured. It may be necessary to treat
					 water with activated carbon to eliminate all interferences. If individual
					 methods specify additional requirements for the reagent water to be used, these
					 must be followed.
C. Glassware
					 Preparation. Specific requirements in the methods for the cleaning of glassware
					 must be followed. If no specifications are listed, then glassware should be
					 washed in a warm detergent solution and thoroughly rinsed first with tap water
					 and then with reagent water. This cleaning procedure is sufficient for general
					 analytical needs. It is advantageous to maintain separate sets of suitably
					 prepared glassware for the nitrate, mercury, and lead analyses due to the
					 potential for contamination from the laboratory environment. For a summary of
					 glassware cleaning procedures, refer to Chapter IV of the USEPA Manual for the
					 Certification of Laboratories Analyzing Drinking Water.
D. Distilled and deionized water shall have
					 at a minimum, resistivity values between 0.5 to 2.0 megohms-cm (2.0 to 0.5
					 micromhos/cm.) at 25o C. Preferably, distilled and
					 deionized water should have resistivity values greater than 1.0 megohms-cm
					 (less than 1.0 micromhos/cm) at 25oC. When
					 purchasing distilled or deionized water, laboratories should request a list of
					 quality specifications for the water purchased. Containers of distilled or
					 deionized water should be capped when not in use and should be capped
					 immediately after each use.
E. All
					 solutions shall be properly labeled with identification of the compound,
					 concentration, solvent, date, and analyst who prepared the solution.
F. All chemicals, solutions, and standards,
					 shall be dated upon receipt by the laboratory; and the date opened by the
					 laboratory shall also be noted.
G.
					 Compositing of samples for inorganic and organic analyses must be done in the
					 laboratory. Samples shall only be composited if the laboratory detection limit
					 is adequate for the number of samples being composited (up to a maximum of
					 five) and the holding times will not be exceeded.
AUTHORITY NOTE:
						Promulgated in accordance with
						R.S.
						36:254(B)(7).