Content accurately Weigh 1.0g, was dissolved in 400 ml of water in a beaker. 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.1000mg/kg
(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.
(1) basic lead acetate solution to take basic lead acetate 80g, so dissolved in 220 ml of water and stirred overnight, filter No. 42 filter paper (or equivalent product). Then the supernatant was diluted with freshly boiled water to the relative density of 1.254.
(2) copper reagent liquid anhydrous disodium hydrogen phosphate 28g and potassium sodium tartrate (KNaC4H4O6 4H2O) 40g dissolved in 700ml of water. Added 1mol / L sodium hydroxide 100 ml, 8 g of copper sulfate pentahydrate, coupled over anhydrous sodium sulfate, 180g. Potassium iodate 0.7134g, and then diluted to 1000 ml. The solution was allowed to stand for a few days later, at the top of the supernatant through a medium porosity sintered glass funnel and the filter.
(3) glucose standard solution Accurately weigh of dried glucose (140 mg) was dissolved in 500 ml of water.
(4) Disodium hydrogen phosphate solution was taken heptahydrate disodium hydrogen phosphate, 19g, was dissolved in 100 ml of water.
(5) The operation was accurately weighed and the sample 1g, dissolved in i50ml water, and the pH value was adjusted to 6.9 ~ 7.2 with sodium hydroxide or acetic acid. Gradually adding basic lead acetate solution, to no longer feel progress = step precipitation occurs. Add water to 250.0 Mix well: the mixture was centrifuged; draw 10 ml of the supernatant was transferred to a 50 ml volumetric flask, and then diluted to approximately 35rnl. Plus disodium hydrogen phosphate solution 2ml or more ¯ to no longer precipitate appears. Diluted to 50 ml with water and mix. Centrifuged at 2100 times gravity 10min. Draw 5 ml of the supernatant was placed in a test tube, add notes reagent solution 5ml, mixed. Loosely stuffed mouth of the tube will be placed in a boiling water bath for 40min ± 10s. After heating, the test tube immediately in cold water will cool. Plus 2.5% potassium iodide solution 2ml and 2 mol / L sulfuric acid 1.5ml. Thoroughly mixed with 0.005 mol / L sodium thiosulfate, using starch indicator, record the consumption volume of anger. Glucose standard solution (glucose standard the liquid 5rnl plus copper reagent 5ml) repeat the above operation, recording the consumption volume for ‰. Above each titration with 5 ml of water and bml copper reagent solution as a blank, blank titration, set the consumption volume for ‰.
50% viscosity of the sample solution Accurately weigh to dry the base of the specimen 200g, dissolved in 200 ml of water served in a 500ml beaker. The solution was then equilibrated at 25 ° C under a Brookfield viscometer A (LVG, or equivalent product), using a No. 2 rotor under 20r/min Determination of the viscosity of the solution.
Packaging, storage and transportation
- Packing: lined with plastic film for external use double packaging PP woven bag, net weight 25kg / package.
- 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: Calcium lignosulfonateis non-toxic and harmless, the Department of non-inflammable and explosive dangerous goods. By car, train transportation is available.