ASTM: D4327: Anions in Water by Ion Chromatography

Summary
Analytes
Revision
Data and Sites

Official Method Name

Standard Test Method for Anions in Water by Chemically Suppressed Ion Chromatography

Current Revision

1997

Media

WATER

Instrumentation

Ion Chromatography

Method Subcategory

Inorganic

Method Source

ASTM

Citation

Annual Book of ASTM Standards, Section 11, Water and Environmental Technology, Volume 11.01, Water (I)

Brief Method Summary

An aliquot of sample is injected into an ion chromatograph. The sample is pumped through two columns and a suppressor device and into a conductivity detector. The analytical column and the guard column are packed with low-capacity anion exchanger. Ions are separated based on their affinity for the exchange sites of the resin. The suppressor device contains a fiber or membrane based cation exchanger which is continuously regenerated by a flow of dilute sulfuric acid. The suppressor device reduces the background conductivity of the eluent to a low or negligible level by replacing the cations with the hydrogen ion, thereby converting the anions in the sample to their corresponding acids. The separated anions in their acid form are measured using an electrical-conductivity cell. Anions are identified based on their retention times compared to known standards. Quantitation is accomplished by measuring the peak height or area and comparing it to a calibration curve generated from known standards.

Scope and Application

This test method covers the sequential determination of fluoride, chloride, nitrite, ortho-phosphate, bromide, nitrate, and sulfate ions in water by chemically suppressed ion chromatography.

Applicable Concentration Range

Varies by analyte (mg/L).

Interferences

Since chloride and nitrite elute very close together, they are potential interferents for each other. As with other types of chromatography, if one of the sample components is present at very high levels, it may interfere by causing a very large peak on the chromatogram which could mask other peaks present. Water from the sample injection will cause a negative peak or dip in the chromatogram when it elutes, because its conductivity is less than that of the suppressed eluent. Due to the effect of the water dip and the interference of organic acids and due to the presence of carbonate ions in the separator column, the user of this test method is urged to use caution when determining fluoride.

Quality Control Requirements

See ASTM Practice D2777 for general information.

Sample Handling

Collect the sample in accordance with D1066 and D3370, as applicable. Analyze samples soon after collection. Preserve samples containing nitrite, nitrate, or phosphate by refrigeration at 4 degrees C. Filter samples containing particulates through a prewashed 0.22-um filter.

Maximum Holding Time

Relative Cost

$51 to $200

Sample Preparation Methods

Collect the sample in accordance with Pr

This method has 7 analytes associated with it.

Analyte	Detection Level	Bias	Precision	Spiking Level
Bromide(24959-67-9) Bromide Bromide (9CI) Bromide ion (-1)	0.630 mg/L	110% Rec (ML)	17.00 % RSD (ML)	0.63 mg/L
Chloride(16887-00-6) Chloride Chloride ion	0.780 mg/L	101% Rec (ML)	22.00 % RSD (ML)	0.78 mg/L
Fluoride(16984-48-8) Fluoride	0.260 mg/L	96% Rec (ML)	31.00 % RSD (ML)	0.26 mg/L
Nitrate(14797-55-8) Nitrate Nitrate ion Nitrate-N Nitrates/nitrites Nitrogen, nitrate	0.420 mg/L	100% Rec (ML)	9.50 % RSD (ML)	0.42 mg/L
Nitrite(14797-65-0) Nitrite Nitrite (as ion) Nitrite nitrogen Nitrite-N Nitrites Nitrogen, nitrite	0.360 mg/L	103% Rec (ML)	11.00 % RSD (ML)	0.36 mg/L
Phosphate(14265-44-2) Orthophosphate Orthophosphate, total Phosphate Phosphorus (as phosphate) Phosphorus, phosphate, ortho Reactive phosphorus Total orthophosphate Total phosphorus	0.690 mg/L	100% Rec (ML)	8.70 % RSD (ML)	0.69 mg/L
Sulfate(14808-79-8) Sulfate Sulfate (as ion) Sulphate (as ion)	2.850 mg/L	99% Rec (ML)	11.00 % RSD (ML)	2.85 mg/L

Precision Descriptor Notes:	The collaborative test of this test method was performed in reagent water, drinking water, and a wastewater of choice by 19 laboratories using one operator each. Six levels of concentration were used for seven anions, producing three Youden pairs. Each Youden pair was used to calculate the single operator precision (So). All data were obtained using a non-metallic pump surface to minimize potential metallic contamination to the analytical columns.
Detection Level Note:

Precision Descriptor Notes:

The collaborative test of this test method was performed in reagent water, drinking water, and a wastewater of choice by 19 laboratories using one operator each. Six levels of concentration were used for seven anions, producing three Youden pairs. Each Youden pair was used to calculate the single operator precision (So). All data were obtained using a non-metallic pump surface to minimize potential metallic contamination to the analytical columns.

Detection Level Note:

Revision	PDF/Link
1997

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ASTM: D4327: Anions in Water by Ion Chromatography

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