Standard Methods: 5910B: UV-Absorbing organic constituents by Ultraviolet Absorption
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Official Method Name
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Ultraviolet Absorption Method |
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Current Revision
| Standard Methods Online |
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Media
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WATER |
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Instrumentation
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Spectroscopy (Colorimetry; Photometry) |
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Method Subcategory
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Organic |
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Method Source
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Citation
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Brief Method Summary
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UV-absorbing organic constituents in a sample absorb UV light in proportion to their concentration. Samples are filtered to control variations in UV absorption caused by particles. Adjustment of pH before filtration is optional. UV absorption is measured at 253.7 nm. |
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Scope and Application
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This method covers the determination of UV-absorbing organic constituents in water and wastewater. |
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Applicable Concentration Range
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None given |
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Interferences
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The primary interference in UV-absorption measurements are from colloidal particles, UV-absorbing organics other than those of interest, and UV-absorbing inorganics, notably ferrous iron, nitrate, nitrite, and bromide. Certain oxidants and reducing agents, such as ozone, chlorate, chlorite, chloramines, and thiosulfate, also will absorb UV light at 253.7 nm. |
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Quality Control Requirements
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For replicate measurements, use at least two portions of filtered sample. For duplicate analyses, analyze every tenth sample in duplicate to assess method precision. |
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Sample Handling
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Wash filter and filter assembly by passing at least 50 mL organic-free water through the filter. For specific applications and correlations, sample pH may be adjusted with HCl or NaOH. In poorly buffered samples, an appropriate non-UV absorbing buffer system such as phosphate buffer may be used. Once sample pH has been adjusted and/or measured, filter sample. |
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Maximum Holding Time
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None given |
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Relative Cost
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Less than $50 |
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Sample Preparation Methods
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