ASTM D4085-93 (R2021) pdf free download.Standard Test Method for Metals in Cellulose by Atomic Absorption Spectrophotometry.
1.1 This test method covers the determination of the iron, copper. manganese, and calcium content of cellulose pulp from wood or cotton.
1 .2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
3. Summary of Test Method
3.1 The sample is ashed in accordance with Test Methods D3516.
3.2 This test method is dependent on the fact that metallic elements in the ground state will absorb light of the same wavelength they emit when excited. When radiation from a given excited element is passed through a flame containing ground-state atoms of that clement, the intensity of the transmitted radiation will decrease in proportion to the amount of the ground-state element in the flame. A hollow cathode lamp whose cathode is made of the element to be determined provides the radiation. The metal atoms to be measured are placed in the beam of radiation by aspirating the specimen into an oxidant-fuel flame. A monochrornator isolates the characteristic radiation from the hollow cathode lamp and a photosensitive device measures the attenuated transmitted radiation.
4. Significance and Use
4.1 Manganese in pulp acts as a catalyst in oxidizing cellulose.
4.2 Iron in pulp can cause yellowness in rayon fibers and influence cellulose acetate plastics color. Iron also causes problems in photographic and blueprint papers.
4.3 Copper in pulp can act as a retardant in oxidizing cellulose and can affect viscose ripening. Copper interferes with the dye level of rayon fibers and influences cellulose acetate plastics color.
4.4 Calcium in pulps can cause problems in processing into acetate, rayon, cellophane. etc. Calcium can create undesirable deposits in viscose spinning and film casting operation. Calcium can influence viscosity control during cellulose acetate manufacture.
5. Apparatus
5. 1 Atoiiiic Ab.sorptioiz SpectroIiotoinerer, consisting of an atomizer and burner, suitable pressure-regulating devices capable of maintaining constant oxidant and fuel pressure for the duration of the test, a hollow cathode lamp for each metal to be tested, an optical system capable of isolating the desired line of radiation, an adjustable slit. a photomultiplicr tube or other photosensitive device, and a read-out mechanism for indicating the amount of absorbed radiation.ASTM D4085 pdf download.