How to analyze calcium lignosulfonate1
Sulfonate sulfur content accurately Weigh 1.0g, was dissolved in 400 ml of water in a beaker Sheng. Slowly to send a stream of nitrogen through the surface of the liquid.
Add 10 ml of nitric acid solution and shake it vigorously until the calm reaction. 70% perchloric acid 10ml, shake it vigorously again. Will not capped beaker was put on a hot plate, strongly contents were heated to the center of the bottom of the beaker became clarity. Remove the beaker and cooled to room temperature.
Add 5 ml of hydrochloric acid, heated to white smoke. After cooling, diluted with water to approximately 100 ml and washed with 10% sodium hydroxide solution was adjusted to pH 6 ± 0.2. The solution was then heated to boiling, add 10% barium chloride solution 15ml beaker was kept overnight at 90 ~ 95 ℃ steam bath.
Having ashless filter paper (No. 42, or equivalent product) was filtered, rinsed with 200 ml of warm water. Filter paper speed clocked into a constant crucible with precipitate. Slowly heated crucible on the Bunsen burner to get rid of the water. The ignition then at 850 ° C in a muffle furnace faint 1h. Remove the weighed after cooling in a desiccator, particle size nearly 0.0001g.
(1) Under stirring, the strontium chloride solution of 60% perchloric acid in 164.7g Sheng 500 ml of distilled water in a 1L beaker. Then add hexahydrate, strontium chloride 15.2 g, stirring until completely dissolved. This solution is transferred to a 1L volumetric flask, make up volume with distilled water at room temperature. Gasser upside down several times to mix the contents.
(2) standard solution with a certified calcium standard solution (Mallinckrodt, or equivalent product), and gradually diluted quantitatively into a calcium content of a standard solution of 0.7mg/ml, stored in a polyethylene bottle.
(3) the sample solution accurately weighed pre the dried sample 1g, diluted to (10.0 ml) and then potassium carbonate. Particle in the sample liquid, and another filter by a 0.45μmMillipore filter, and discard a certain initial filtrate. Draw 5 ml of strontium chloride solution put 50ml volumetric flask, plus the filtrate 5.0ml, and then diluted to a predetermined volume and mix.
(4) operating with a suitably calibrated atomic absorption spectrophotometer according to a predetermined step of the instrument, the absorbance of the standard solution and the sample solution was measured at 422.7nm. Shall not be greater than the absorbance of the sample solution from the standard solution.
Packaging, storage and transportation
1, Packing: lined with plastic film for external use double packaging PP woven bag, net weight 25kg / package.
2, Storage: Store in a dry and well-ventilated place, should pay attention to moisture vapor barrier. Long-term storage is not bad, if agglomeration does not affect the results, crushed or dissolved.
Transportation: This product is non-toxic and harmless, the Department of non-inflammable and explosive dangerous goods. By car, train transportation is available.