ASTM International

Standard Test Method for Anions in Water by Suppressed Ion Chromatography
 N D4327

Annotation

This test method2 covers the sequential determination of fluoride, chloride, nitrite, ortho-phosphate, bromide, nitrate, and sulfate ions in water by suppressed ion chromatography.

NOTE 1—Order of elution is dependent upon the column used;

This test method is applicable to drinking and wastewaters. The ranges tested for this test method for each anion were as follows (measured in mg/L):

It is the user's responsibility to ensure the validity of this test method for other matrices.

Concentrations as low as 0.01 mg/L were determined depending upon the anions to be quantified, in single laboratory work. Utilizing a 50- L sample volume loop and a sensitivity of 3 S/cm full scale, the approximate detection limits shown in Table 1 can be achieved. Lower detection limits have been observed with newer instrumentation, column technology and eluents. The analyst must assure optimum instrument performance to maintain a stable baseline at more sensitive conductivity full-scale settings.

The upper limit of this test method is dependent upon total anion concentration and may be determined experimentally as described in Annex A1. These limits may be extended by appropriate dilution or by use of a smaller injection volume.

Using alternate separator column and eluents may permit additional anions such as acetate, formate or citrate to be determined. This is not the subject of this test method.

This method update approves the use of Electrolytically generated eluent, electrolytically regenerated eluent, electrolytic suppression (not autozeroing) and electrolytic trap columns also known as Reagent Free Ion Chromatography. This approval is based on acceptance by the US EPA as referenced in Appendix X2