This standard test method covers the determination of silicon in engine coolant concentrates by atomic absorption spectroscopy. Apparatus and reagents used for this test method include atomic absorption spectrometer, hollow-cathode lamp, reagent grade chemicals, standard silicon solution, ethylene glycol or propylene glycol, and sodium hydroxide. Silicon content shall be determined from an established standard curve and an atomic absorption spectrometer. A nitrous oxide-acetylene flame shall be used.

1.1 This test method covers the determination of silicon in the range from 200 to 500 ppm in engine coolant concentrates by atomic absorption. This method is as accurate and precise as photometric methods, while requiring considerably less operator time and avoiding problems with reagent instability.

1.1.1 Coolants with silicon content outside of this range may be analyzed by this method by suitably adjusting the sample size. Care should be taken to ensure that the glycol content of the working standards corresponds to that of the sample solution being analyzed.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.