ASTM D6069 Test Method for Trace Nitrogen in Aromatic Hydrocarbons
ASTM D6069 Standard Test Method for Trace Nitrogen in Aromatic Hydrocarbons by Oxidative Combustion and Reduced Pressure Chemiluminescence Detection
9. Hazards
9.1 Consult current OSHA regulations, suppliers' Material Safety Data Sheets, and local regulations for all materials used in this test method.
9.2 High temperature is employed in this test method. Warning - Extreme care should be exercised when using flammable materials near the pyrolysis furnace.
10. Sample Handling
10.1 Collect the samples in accordance with Practice D3437.
10.2 To preserve sample integrity (consistency) and prevent the loss of volatile components, which may be in some samples, do not uncover samples any longer than necessary. Analyze specimen as soon as possible after transferring from the sample container to prevent loss of nitrogen or contamination.
10.3 Since this procedure is intended for trace level contamination, care must be taken to ensure the containers used for the sample, the specimen, and the working standard do not alter the sample results.
11. Instrument Assembly and Preparation
11.1 Install the instrument in accordance with manufacturer's instructions.
11.2 Adjust gas flows and pyrolysis temperature(s) to the operating conditions as recommended by the manufacturer.
11.3 The actual operation of injecting a sample will vary depending upon the instrument manufacturer and the type of inlet system used (see 7.5-7.8).
12. Calibration and Standardization
12.1 Prepare the working calibration standards using the stock solution as described in 8.5 and 8.6.
12.1.1 Before injecting a standard or blank, refer to procedures (see Section 13, Procedure), to ensure proper technique for either the direct injection system or the boat inlet system.
12.2 A calibration based on the difference between two gravimetrically prepared standards works well within the limited scope of this procedure. This type of calibration can be used to quantitate nitrogen at the 1.0 ppm (wt/wt) concentration or to determine pass/fail compliance. Two standards are prepared with concentrations that differ by the target specification. Thus, for a 1.0 ppm nitrogen (wt/wt) maximum specification, prepare two standards that differ in concentration by 1.0 ppm (that is, 2.0 µg-N/mL and a 1.0 µg-N/mL standard).
12.2.1 Each standard should be injected in triplicate and the integrator counts averaged and recorded.
