ASTM D6560 Test Method for Determination of Asphaltenes (Heptane Insolubles)
ASTM D6560 Standard Test Method for Determination of Asphaltenes (Heptane Insolubles) in Crude Petroleum and Petroleum Products
9. Test Portion Preparation
9.1 Test portions from the laboratory samples shall be drawn after thorough mixing and subdivision. Heat viscous samples of residual fuels to a temperature that renders the sample liquid, but not above 80°C, and homogenize, using the mixer (see 6.16) as necessary.
9.2 Heat samples of penetration grade bitumens to a temperature not exceeding 120°C, and stir well before taking an aliquot.
9.3 Samples of hard bitumens shall be ground to a powder before an aliquot is taken.
9.4 Samples of crude petroleum shall be prepared in accordance with the procedure described in the Annex A1, unless it is known that the crude petroleum contains negligible quantities of material boiling below 80°C.
10. Apparatus Preparation
10.1 Clean all glass flasks (see 6.4) and dishes (see 6.6) by a means that matches the cleanliness obtained by the use of a strongly oxidizing agent, such as chromosulfuric acid, ammonium peroxydisulfate in concentrated sulfuric acid at approximately 8 g/L, or sulfuric acid itself, soaking for at least 12 h, followed by rinses in tap water, distilled water, and then acetone, using forceps only for handling. (Warning - Chromosulfuric acid is a health hazard. It is toxic, a recognized carcinogen as it contains Cr (VI) compounds, which are highly corrosive and potentially hazardous in contact with organic materials. When using chromosulfuric acid cleaning solution, eye protection and protective clothing are essential. Never pipette the cleaning solution by mouth. After use, do not pour cleaning solution down the drain, but neutralize it with great care, owing to the concentrated sulfuric acid present, and dispose of it in accordance with standard procedures for toxic laboratory waste (chromium is highly dangerous to the environment). Nonchromium containing, strongly oxidizing acid cleaning solutions are also highly corrosive and potentially hazardous in contact with organic materials, but do not contain chromium, which has its own special disposal problems.
10.2 For routine analysis, use a proprietary laboratory detergent to clean the glassware, followed by the rinses described in 10.1. When the detergent cleaning no longer matches the cleanliness required based on visual appearance, use a strong oxidizing agent.
10.3 After rinsing, place the glassware in the oven (see 6.12) for 30 min, and cool in the cooling vessel (see 6.15) for 30 min before weighing.
