ASTM: D5904: Carbon (all forms) in Water

Summary
Analytes
Revision
Data and Sites

Official Method Name

Standard Test Method for Total Carbon, Inorganic Carbon, and Organic Carbon in Water by Ultraviolet, Persulfate Oxidation, and Membrane Conductivity Detection

Current Revision

Current edition approved Feb. 10, 1996.

Media

WATER

Instrumentation

Total Organic Carbon Analyzer

Method Subcategory

Organic

Method Source

ASTM

Citation

Annual Book of ASTM Standards, Section 11, Water and Environmental Technology, Volume 11.02, Water (I)

Brief Method Summary

The basic steps of this test method are: 1)Removal of IC, if desired, by vacuum degassing; 2)Conversion of remaining inorganic carbon to CO₂ by action of acid in both channels and oxidation of total carbon to CO₂ by action of acid-persulfate, aided by ultraviolet (UV) radiation in the TC channel; 3) Detection of CO₂ that is swept out of the reactors by the liquid stream over membranes that allow the specific passage of CO₂ to high purity water where change in conductivity is measured; and 4) Conversion of the conductivity detector signal to a display of carbon concentration in parts per million (ppm = mg/L) or parts per billion (ppb = ug/L). The IC channel reading is subtracted from the TC channel to give a TOC reading.

Scope and Application

This method determines total carbon (TC), inorganic carbon (IC), and total organic carbon (TOC) in water.

Applicable Concentration Range

0.5 - 30 mg/L

Interferences

Chloride ion above 250 mg/L tends to interfere with oxidative reaction mechanisms in this test method. Follow manufacturer's instructions for dealing with this problem. Other interferences have been investigated and found to be minimal under most conditions.
Use of the vacuum degassing unit or sparging the sample may cause loss of volatile organic compounds, thus yielding a value lower than the true TOC level. At low TOC levels, the degassing unit may introduce a measurable TOC and IC background. The user should characterize the background and performance of the degassing module for their application. A removal efficiency of 97 % of the inlet IC is considered satisfactory.

Quality Control Requirements

Instrument calibration must be checked at the start of each sample group.
A duplicate, blank, and continuing calibration check sample must be run at least every twenty samples.

Sample Handling

Collect the sample in accordance with Specification D 1192 and Practices D 3370.
To preserve samples for this analysis, store samples in glass at 4^oC. To aid preservation, acidify the samples to a pH of 2. It should be noted that acidification will enhance loss of inorganic carbon. If the purgeable organic fraction is important, fill the sample bottles to overflowing with a minimum of turbulence and cap them using a fluoropolymer-lined cap, without headspace.
For monitoring of waters containing solids or immiscible liquids that are to be injected into the reaction zone, use a mechanical homogenizer or ultrasonic disintegrator. Filtering or screening may be necessary after homogenization to reject particle sizes that are too large for the sample inlet tube or autosampler needle. Volatile organics may be lost.
For accurate measurements of samples containing < 0.5 mg/L direct, on-line measurement should be used.

Maximum Holding Time

Relative Cost

$51 to $200

Sample Preparation Methods

This method has 1 analyte associated with it.

Analyte	Detection Level	Bias	Precision	Pct False Positive	Pct False Negative	Spiking Level
Total Organic Carbon(E-10195) Organic carbon, total TOC Total Organic Carbon Total organic carbon	0.500 mg/L	97% Rec (ML)	4.30			1.25 mg/L

Precision Descriptor Notes:	This method was evaluated at seven laboratories. Three labs used two different instrument models, and one lab used two different operators. Four samples were analyzed at each laboratory in triplicate on three different days for total inorganic carbon (TIC), total carbon (TC) and total organic carbon (TOC). The study samples included a reagent blank (Type II water), two standards made from potassium acid phthalate and one standard made from fulvic acid, which also contained carbonate and chloride.
Detection Level Note:	None.

Precision Descriptor Notes:

This method was evaluated at seven laboratories. Three labs used two different instrument models, and one lab used two different operators. Four samples were analyzed at each laboratory in triplicate on three different days for total inorganic carbon (TIC), total carbon (TC) and total organic carbon (TOC). The study samples included a reagent blank (Type II water), two standards made from potassium acid phthalate and one standard made from fulvic acid, which also contained carbonate and chloride.

Detection Level Note:

None.

Revision	PDF/Link
Current edition approved Feb. 10, 1996.

The Water Quality Portal contains sample results from sites that use this method.

Download WQP data

Select data:

Sites only
Sample results only

File format:

Comma-separated
Tab-separated
MS Excel 2007+

Sites where this method was used

Loading Sites ...

ASTM: D5904: Carbon (all forms) in Water

WHO WE ARE

LEGAL