化验用水标准

yc2006

化验室用水标准可以参照ASTM规定的type 1 water 级别高于通常的纯化水和蒸馏水，相当于超纯水

ASTM （American Society for Testing and Materials）
D1193-99e1 Standard Specification for Reagent Water

1. Scope

1.1 This specification covers requirements for water suitable for use in methods of chemical analysis and physical testing. Four grades are specified:

Type I Type II Type III Type IV
Electrical conductivity, max, μS/cm at 298 K (25oC) 0.056 1.0 0.25 5.0
Electrical resistivity, min, Mcm at 298 K (25oC) 18 1.0 4.0 0.2
pH at 298 K (25oC) A  A A 5.0 to 8.0
Total organic carbon (TOC), max, μg/L 50 50 200 no limit
Sodium, max, μg/L 1 5 10 50
Chlorides, max, μg/L 1 5 10 50
Total silica, max, μg/L 3 3 500 no limit
Microbiological contamination-When bacterial levels need to be controlled, reagent grade types should be further classified as follows:  Type A Type B Type C
Maximum heterotrophic bacteria count  10/1000 mL 10/100 mL 100/10 mL
Endotoxin, EU/mlB  0.03 0.25 not applicable
AThe measurement of pH in Type I, II, and III reagent waters has been eliminated from this specification because these grades of water do not contain constituents in sufficient quantity to significantly alter the pH.
B EU = Endotoxin Units.

1.2 The method of preparation of the various grades of reagent water determines the limits of impurities and shall be as follows:

1.2.1 Type I grade of reagent water shall be prepared by distillation or other equal process, followed by polishing with a mixed bed of ion exchange materials and a 0.2-μm membrane filter. Feedwater to the final polishing step must have a maximum conductivity of 20 μS/cm at 298K (25oC).

1.2.2 Type II grade of reagent water shall be prepared by distillation using a still designed to produce a distillate having a conductivity of less than 1.0 μS/cm at 298 K (25oC). Ion exchange, distillation, or reverse osmosis and organic adsorption may be required prior to distillation if the purity cannot be attained by single distillation.

Note 1—Because distillation is a process commonly relied upon to produce high purity water, the levels specified for Type II reagent water were selected to represent the minimum quality of water that a distillation process should produce.

1.2.3 Type III grade of reagent water shall be prepared by distillation, ion exchange, continuous electrodeionization reverse osmosis, or a combination thereof, followed by polishing with a 0.45-μm membrane filter.

1.2.4 Type IV grade of reagent water may be prepared by distillation, ion exchange, continuous electrodeionization reverse osmosis, electrodialysis, or a combination thereof.

1.3 The choice of one of the various grades may be designated by the method or by the investigator.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.



2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ASTM Standards

D1125 Test Methods for Electrical Conductivity and Resistivity of Water

D1129 Terminology Relating to Water

D1293 Test Methods for pH of Water

D4453 Practice for Handling of High Purity Water Samples

D4517 Test Method for Low-Level Total Silica in High-Purity Water by Flameless Atomic Absorption Spectroscopy

D5128 Test Method for On-Line pH Measurement of Water of Low Conductivity

D5173 Test Method for On-Line Monitoring of Carbon Compounds in Water by Chemical Oxidation, by UV Light Oxidation, by Both, or by High Temperature Combustion Followed by Gas Phase NDIR or by Electrolytic Conductivity

D5245 Practice for Cleaning Laboratory Glassware, Plasticware, and Equipment Used in Microbiological Analyses

D5391 Test Method for Electrical Conductivity and Resistivity of a Flowing High Purity Water Sample

D5542 Test Methods for Trace Anions in High Purity Water by Ion Chromatography

D5997 Test Method for On-Line Monitoring of Total Carbon, Inorganic Carbon in Water by Ultraviolet, Persulfate Oxidation, and Membrane Conductivity Detection

D6071 Test Method for Low Level Sodium in High Purity Water by Graphite Furnace Atomic Absorption Spectroscopy

D6161 Terminology Used for Microfiltration, Ultrafiltration, Nanofiltration and Reverse Osmosis Membrane Processes

D6529 Test Method for Operating Performance of Continuous Electrodeionization Systems on Feeds from 50-1000 S/cm

F1094 Test Methods for Microbiological Monitoring of Water Used for Processing Electron and Microelectronic Devices by Direct Pressure Tap Sampling Valve and by the Presterilized Plastic Bag Method

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