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Hydroxypropyl Potato Starch Before the Last Few Ml of Hydrochloric Acid Drain Out

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Hydroxypropyl Potato Starch Before the Last Few Ml of Hydrochloric Acid Drain Out NF 31 Official Monographs / Starch 2239 film of stopcock grease to the sealing surfaces of all of • LOSS ON DRYING 〈731〉 the joints except the joint between the separatory fun- Sample: 1 g nel and the boiling flask, and clamp the joints to ensure Analysis: Dry the Sample at 130° for 90 min. tightness. Acceptance criteria: NMT 20.0% Sample: 25.0 g of Potato Starch • PH 〈791〉 Analysis: Add 150 mL of water to the boiling flask. Sample solution: Prepare a slurry by weighing 5.0 g of Close the stopcock of the separatory funnel, and begin Potato Starch, transferring to a suitable nonmetallic the flow of carbon dioxide at a rate of 100 ± 5 mL/min container, and adding 25.0 mL of freshly boiled and through the Apparatus. Start the condenser coolant cooled water. flow. Add 10 mL of Hydrogen peroxide solution to a re- Analysis: Agitate continuously at a moderate rate for 1 ceiving test tube. After 15 min, without interrupting the min. Stop the agitation, and allow to stand for 15 min. flow of carbon dioxide, remove the separatory funnel Determine the pH to the nearest 0.1 unit. from the boiling flask, and transfer the Sample into the Acceptance criteria: 5.0±8.0 boiling flask with the aid of 100 mL of water. Apply stopcock grease to the outer joint of the separatory fun- ADDITIONAL REQUIREMENTS nel, and replace the separatory funnel in the boiling • NPACKAGING AND STORAGE: Preserve in well-closed flask. Close the stopcock of the separatory funnel, and containers. No storage requirements specified.N add 80 mL of 2 N hydrochloric acid to the separatory funnel. Open the stopcock of the separatory funnel to permit the hydrochloric acid solution to flow into the boiling flask, guarding against the escape of sulfur diox- . ide into the separatory funnel by closing the stopcock Hydroxypropyl Potato Starch before the last few mL of hydrochloric acid drain out. Boil the mixture for 1 h. Remove the receiving test tube, and transfer its contents to a 200-mL wide- necked, conical flask. Rinse the receiving test tube with a small portion of water, add the rinsing to the 200-mL conical flask, and mix. Heat on a water bath for 15 min, and allow to cool. Add 0.1 mL of Bromophenol blue indicator solution, and titrate the contents with 0.1 N sodium hydroxide VS until the color changes from yellow to violet-blue. Per- form a blank determination, and make any necessary correction (see Titrimetry 〈541〉). Calculate the content, in ppm, of sulfur dioxide in the For the Amylose derivative, m is about 300±1000. Sample taken: DEFINITION Result = 1000 × 32.03 × (VN/W) Hydroxypropyl Potato Starch is partially substituted 2-hydroxypropylether obtained from potato starch by a 32.03 = milliequivalent weight of sulfur dioxide chemical modification of etherification with propylene ox- V = volume of titrant consumed (mL) ide. In addition, this starch may be partially hydrolyzed N = normality of the titrant using acids or enzymes to obtain thinned starch. It con- W = weight of the Sample (g) tains NLT 2.0% and NMT 7.0% of hydroxypropyl groups, Acceptance criteria: NMT 50 ppm on the dried basis. • LIMIT OF OXIDIZING SUBSTANCES Sample solution: Transfer 4.0 g to a glass-stoppered, IDENTIFICATION 125-mL conical flask, and add 50.0 mL of water. Insert • A. PROCEDURE the stopper, and swirl for 5 min. Transfer to a glass- Analysis: Examine under a microscope, using NLT 20× stoppered, 50-mL centrifuge tube, and centrifuge to magnification and a mixture of glycerin and water (1:1) clarify. Transfer 30.0 mL of the clear supernatant to a as a mounting agent. glass-stoppered, 125-mL conical flask. Add 1 mL of Acceptance criteria: It presents granules, either irregu- glacial acetic acid and 0.5±1.0 g of potassium iodide. larly shaped, ovoid or pear-shaped, usually 30±100 µm Insert the stopper, swirl, and allow to stand for 25±30 in size, but occasionally exceeding 100 µm, or rounded min in the dark. Add 1 mL of starch TS. 10±35 µm in size. There are occasional compound Analysis: Titrate with 0.002 N sodium thiosulfate VS to granules having 2±4 components. The ovoid and pear- the disappearance of the starch±iodine color. Perform a shaped granules have an eccentric hilum, and the blank determination, and make any necessary rounded granules have a centric or slightly eccentric hi- correction. Each mL of 0.002 N sodium thiosulfate is lum. All granules show clearly visible concentric stria- equivalent to 34 µg of oxidant, calculated as hydrogen tions. Between crossed nicol prisms, the Hydroxypropyl peroxide. Potato Starch granules show a distinct black cross inter- Acceptance criteria: NMT 1.4 mL of 0.002 N sodium secting at the hilum. thiosulfate is required (20 ppm, calculated as H2O2). • B. PROCEDURE Sample solution: Suspend 1 g of Hydroxypropyl Potato SPECIFIC TESTS Starch in 50 mL of water, boil for 1 min, and cool. • MICROBIAL ENUMERATION TESTS 〈61〉 and TESTS FOR Acceptance criteria: A translucent or clear mucilage is SPECIFIED MICROORGANISMS 〈62〉: The total aerobic formed. microbial count does not exceed 103 cfu/g; the total • C. PROCEDURE combined molds and yeasts count does not exceed 102 Analysis: To 1 mL of the Sample solution obtained in cfu/g; and it meets the requirements of the test for the Identification test B add 0.05 mL of iodine and potas- absence of Escherichia coli. sium iodide TS 2. Acceptance criteria: An orange-red to dark blue color is produced, which disappears upon heating. • D. PROCEDURE Ninhydrin solution: Dissolve 3 g of ninhydrin in 100 mL of a 45.5-g/L solution of sodium metabisulfite. 2240 Starch / Official Monographs NF 31 Diluted sulfuric acid: 98 g/L of H2SO4 and of the methyl groups at 0 ppm of the internal stan- 13 Sample: 100 mg of Hydroxypropyl Potato Starch dard (A1) without C-satellites. Analysis: Transfer the Sample to a 100-mL volumetric Measure the signal coming from the 3 protons of the flask, and add 12.5 mL of Diluted sulfuric acid. Place the methyl group in the hydroxypropyl function. flask in a water bath, and heat until the Sample is dis- Calculate the content of hydroxypropyl groups as a per- solved. Cool, and dilute with water to 100 mL. [CAU- centage (w/w, dried basis): TIONÐWhen sulfuric acid is miscible with water, it pro- duces intense heat.] Result = (N × A2/A1) × (Ci × Wi/W) × (Mr2/Mr1) × [100/ Pipet 1 mL of this solution to a glass-stoppered, 25-mL (100 − B)] × 100 graduated test-tube and, with the tube immersed in cold water, add drop-wise 8 mL of sulfuric acid. Mix N = numerical value representing the 3 methyl well, and place the tube in a boiling water bath for groups in the internal standard (sodium exactly 3 min. Immediately transfer the tube to an ice 3-trimethylsilyl-1-propane sulfonate), 3 bath until the solution is chilled. Add 0.6 mL of A2 = area of the methyl groups of hydroxypropyl in Ninhydrin solution, carefully allowing the reagent to run Hydroxypropyl Potato Starch down the walls of the test tube. Immediately shake the A1 = area of the methyl groups in the internal tube well, and place it in a water bath at 25° for 100 standard (sodium 3-trimethylsilyl-1-propane min. Dilute with sulfuric acid to 25 mL [CAUTIONÐUse sulfonate) sulfuric acid cautiously.], and mix by inverting the tube Ci = concentration of the internal standard in the several times. Do not shake. Internal standard solution (mg/g) Acceptance criteria: A violet color develops within 5 Wi = weight of the Internal standard solution in the min due to the presence of hydroxypropyl groups NMR tube (g) (starch ether). W = weight of the washed and dried Hydroxypropyl Potato Starch in the NMR ASSAY tube (mg) • PROCEDURE FOR HYDROXYPROPYL GROUPS Mr1 = molecular weight of the internal standard, Deuterium chloride solution: Dilute 1 mL of deuterium 218.32 g/mol chloride (38% w/w) with 5 mL of deuterium oxide. Mr2 = molar mass of hydroxypropyl group, 59.09 g/ Internal standard solution: Dissolve 50.0 mg of so- mol dium 3-trimethylsilyl-1-propane sulfonate in about 5 g B = moisture content of the washed and dried of deuterium oxide, weighed to the nearest 0.1 mg. Hydroxypropyl Potato Starch used in the Store in a sealed bottle. Sample solution, as a percentage (w/w) Sample solution: Disperse 20 g of Hydroxypropyl Po- Acceptance criteria: The content of hydroxypropyl tato Starch in 200.0 mL of carbon dioxide-free water at groups is 2.0%±7.0% on the dried basis. room temperature. Agitate for 15 min, and filter. Re- peat the operation two more times. If poor dispersibility IMPURITIES or slow filtration is observed, use refrigerated carbon Inorganic Impurities dioxide-free water for the washing operation. Dry the • RESIDUE ON IGNITION 〈281〉: NMT 0.6%, determined on a washed starch for NLT 4 h in vacuum at 30 ± 5°. Deter- 1.0-g test specimen mine the moisture content (B) on 5 g of the washed • LIMIT OF IRON and dried starch following the Loss on Drying test. Standard iron stock solution: Prepare a solution Weigh 12.0 mg of the washed and dried starch in a containing the equivalent of 10 µg/mL of iron, as 5-mm NMR tube. Add 0.75 mL of deuterium oxide and directed under Iron 〈241〉. 0.1 mL of Deuterium chloride solution. Cap the tube, Diluted standard iron solution: Immediately before mix, and place it in a boiling water bath until a clear use, dilute an accurately measured volume of Standard solution is obtained.
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