1.1This test method is applicable to the determination of calcium, magnesium, potassium, and sodium in atmospheric wet deposition (rain, snow, sleet, and hail) by flame atomic absorption spectrophotometry (FAAS). (1)²

1.2The concentration ranges are listed below. The range tested was confirmed using the interlaboratory collaborative test (see Table 1 for a statistical summary of the collaborative test).

1.3The method detection limit (MDL) is based on single operator precision (2) and may be higher or lower for other operators and laboratories. Many workers have found that this test method is reliable at lower levels than were tested, but the precision and bias data presented are insufficient to justify their use at lower levels.

1.4The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5This 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. Specific warning statements are given in 8.3, 8.7, 12.1.8, and Section 9.