Abstract
Atomic absorption spectrometry (AAS) and inductively coupled plasma spectrometry (ICP) were applied to analyses of the ash content in particulates emitted from a diesel engine. Particulate samples were decomposed and dissolved by sulfuric acid, nitric acid, aqua regia, hydrochloric acid and hydrogen peroxide. The objective components in ash (calcium, zinc and phosphorus) originating from lubricant additives were determined in order to evaluate the quantity of lubrication oil consumption. ICP was used for the determination of phosphorus because AAS does not have sufficient sensitivity for the component in ash. The calculated values based on these analytical methods showed the same level as the real lubrication oil consumption, and the results were effective for the quantification of lubrication oil consumption, even though the engine operating time was minimized to about one tenth of the conventional weight-change method.