“The bubbling continues, but after approximately an hour at room temperature, the final product begins to crystallize from the solution, again giving a visual clue that another reaction is occurring”. “This second, intermolecular reaction is much slower”. “The reaction continues at room temperature in a lightly corked Erlenmeyer flask until the next lab period, by which time the reaction mixture appears solid with crystalline product”. “The difference in solubility between the starting amphoteric amino acid and the final R-hydroxy acid is worthy of discussion, both compounds have similar molar masses and hydrogen bonding capability, so that the difference in solubility rests in the basicity of the amino group”. “Isolating the product by filtration, rinsing the crystals with chilled water, and allowing the product to dry gives a reasonable yield (45-60%) of fine, off white crystals of sufficient purity for 1 H NMR, melting point, and optical rotation analyses”.
Chloroacetic acid (0.5 g, 5. 28 mmol), 5-aminotetrazole monohydrate (0.45 g, 5. 28 mmol), and sodium hydroxide (0.59 g, 10.57 mmol) in 10 ml of water was refluxed 20 hr, cooled, and made strongly acidic with concentrated hydrochloric acid. The mixture was cooled overnight and precipitate was separated to give 0.28 g a white solid product at 45.41% yield. (5-Amino-tetrazol-1-yl)-acetic acid: Yield: 45.41%; white crystals; m.p 210-213°C; IR (KBr): 3388, 3315, 3270, 3205, 3010, 2976, 1697, 1638, 1586, 1496, 1257 cm-1; 13C NMR (75 MHz (DMSO-d6)): 168, 156, 46.
Solution preparation Primary stock solution of Omeprazole was prepared by dissolving 10 to 12 mg of the drug in methanol and the volume was made up to 10 ml. standard solution of Omeprazole have been prepared in the concentration range of 256.0ng/ml to1000000.00ng/ml by using equal volume mixture of methanol and water. Sample preparation The spiked plasma samples were withdrawn from deep freezer and were allowed to thaw at room temperature .200µl of plasma was into clean RIA vial and 50µl of Omeprazole were added and vortex well.600 µl of carbinol was added to the vial and the samples were mixed well at 2500 rpm for 10 minutes in vibromax shaker. The samples were then centrifuged at 4000rpm for 10minutes at 40c. 100 µl of the supernatant was reconstituted with 900 µl of mobile phase 10 µl were injected into the lc-ms/ms
0.5 grams of NaCl was added, stirred and filtered. The residue was washed with 2M HCl until the volume of the filtrate became 6mL. 1mL of the filtrate was tested with 2-3 drops of Mayer’s reagent, Wagner’s reagent and Draggendorrf’s reagent. The relative amount of precipitation was observed: (+ Slight turbidity), (++ Definite turbidity), (+++ Heavy turbidity). 3.2 Alkaloidal Analysis
(2) Titration of Acetic Acid with Sodium Hydroxide 10ml of distilled water was added into a 250ml Erlenmeyer flask. 20ml of diluted acetic acid was then added into it, followed by setting up a titration system with 0.100M of NaOH in buret. A pH meter was used to monitor the pH of the solution as the base (NaOH) was added. Sodium hydroxide was added in an increment of 1ml until the solution pH reached 4.8. After the solution pH reached, the base was added in an increment of 0.2ml until the equivalence point was passed.
Concentrate the methylene chloride solution of benzyl alcohol by using distillation assembly placed in a water bath, until the volume of the residual liquid reduced to half volume. 4. Cool the remaining liquid, transfer it to a separatory funnel and shake it thoroughly with two 1 mL portions of 20% aqueous sodium bisulfite to remove any benzaldehyde. Wash the methylene chloride solution finally with two 1 mL portions of water and dry it with 0.5-1 g of anhydrous magnesium sulfate. 5.
The phosphoamino acids were eluted with water and dried in vacuo. The residues were dissolved in 30l of a mixture of nonradioactive O-phosphoserine and O-Phosphothreonine ( 5 mg of each /ml ), and 10 l aliquots were used for electrophoresis. The electrophoresis buffer contained 25 ml of 88% of formic acid and 87 ml of glacial acetic acid per litre, pH 1.9. The samples were applied to Whatman No.3 MM paper and electrophoresis was carried for 2 hr and 500 V. A small strip of the paper was stained with phosphate reagent. The rest of the strip was stained with 0.2% ninhydrin in acetone.
• Used a 100 mL beaker and prepared another ice-water bath. • Pipetted 2 mL of Nitric Acid (concentrated) into a clean, dry vial and cooled the vial in the new ice-water bath. • Added 2 mL of sulfuric acid (concentrated) very slowly to the Nitric Acid in the
H2Oup to the mark. If necessary warm slightly. 4. Preparation of stock solution of iron: Weigh and transfer 0.07g of ferrous ammonium sulfate (Fe(NH4)2(SO4)2.6H2O) into a 1L volumetric flask, add water followed by 2.5mL of conc. H2SO4 and dilute to the mark with dist.
It has been prepared with some modifications. ZP was prepared as follows: typically, 5 g ZrOCl2.8H2O was refluxed with 50 ml of 12 M H3PO4 at 100 °C for 24 h. The obtained precipitate was filtered off and washed with 0.1 M H3PO4 until free of chloride ion. Finally, the solid was washed with distilled water several times until the neutral pH and dried in an oven at 110 °C for 24 h. The final product was ground into fine powders and confirmed by XRD (Fig.1). The ZPFe was prepared through an ion-exchange reaction[50, 51] (. 3 g of ZP was dispersed into the 50 ml deionized water at 50 °C.