CARBONIZABLE SUBSTANCES IN PARAFFIN WAX: D612
EXPLANATION
This test method determines the carbonizable substances in pharmaceutical paraffin wax whose quality is prescribed by the U.S. National Formulary. Such waxes have a melting point between 117 and 149° F (47 and 65° C), as determined by Test Method D87.
TEST SUMMARY
Five mL of melted wax are treated with 5 mL of concentrated nitrogen-free sulfuric acid at 158° F (70° C). The color of the acid layer is compared with that of a colorimetric reference standard. If the color is not darker than the standard, then the wax is reported as passing the test.
TEST PRECISION
Since this is a pass-fail test, no precision or bias estimate can be made.
