4. Significance and Use
4.1 Knowledge of the amount of ash-forming material present in a product can provide information as to whether or not the product is suitable for use in a given application. Ash can result from oil or water-soluble metallic compounds or from extraneous solids such as dirt and rust.
5. Apparatus
5.1 Evaporating Dish or Crucible, made of platinum, silica, or porcelain, of 90 mL minimum capacity to 120-mL maximum capacity.
5.2 Electric Muffle Furnace, capable of maintaining a temperature of 775 more or less 25°C and preferably having suitable apertures at the front and rear so as to allow a slow natural draught of air to pass through.
5.3 Meeker Gas Burner, or equivalent.
5.4 Mechanical Shaker
6. Reagents
6.1 Propan-2-ol - (Warning - Flammable, can be explosive when evaporated to or near dryness.)
6.2 Toluene - (Warning - Flammable, toxic.)
6.3 Quality Control (QC) Samples, preferably are portions of one or more liquid petroleum materials that are stable and representative of the samples of interest. These QC samples can be used to check the validity of the testing process as described in Section 11.
7. Sampling
7.1 Obtain samples in accordance with the instructions in Practice D4057 or D4177. Before transferring the portion of the sample to be ashed to the evaporating dish or crucible, take particular care to ensure that the portion taken is truly representative of the larger portion. Vigorous shaking can be necessary.
