EPA-RCA: 9040 B: pH in Water by Electrometric Measurement
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Official Method Name
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pH Electrometric Measurement |
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Current Revision
| Revision 3, November 2004 |
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Media
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WATER |
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Instrumentation
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pH Meter |
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Method Subcategory
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Inorganic |
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Method Source
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Citation
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Brief Method Summary
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The pH of the sample is determined electrometrically using either a glass electrode in combination with a reference potential or a combination electrode. The measuring device is calibrated using a series of standard solutions of known pH. |
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Scope and Application
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Method 9040 is used to measure the pH of aqueous wastes and those multiphase wastes where the aqueous phase constitutes at least 20% of the total volume of the waste. The corrosivity of concentrated acids and bases, or of concentrated acids and bases mixed with inert substances, cannot be measured. The pH measurement requires some water content. |
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Applicable Concentration Range
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None given. |
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Interferences
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(1) Sodium error may bias results at pH > 10 unless a "low sodium error" electrode is used. (2) Coatings of oily material can impair electrode. (3) Temperature effects. |
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Quality Control Requirements
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See Chapter One for information. |
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Sample Handling
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Collect all samples by using a sampling plan that addresses the consideration discussed in Chapter 9. Analyze the samples as soon as possible. |
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Maximum Holding Time
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Samples should be analyzed as soon as possible. |
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Relative Cost
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Less than $50 |
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Sample Preparation Methods
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