Ester value - Revision history

Mireya at 21:14, 14 June 2018

2018-06-14T21:14:01Z

Wikimc at 13:35, 19 August 2013

2013-08-19T13:35:44Z

Wikimc: /* USP 401 */

2013-08-16T17:14:48Z

‎USP 401

Wikimc: /* Method */

2013-08-15T22:31:38Z

‎Method

Wikimc: /* Method */

2013-08-15T22:31:19Z

‎Method

Wikimc at 17:17, 15 August 2013

2013-08-15T17:17:30Z

Wikimc at 17:15, 15 August 2013

2013-08-15T17:15:35Z

Wikimc: /* USP 401 */

2013-08-15T17:15:05Z

‎USP 401

Wikimc at 17:14, 15 August 2013

2013-08-15T17:14:21Z

Wikimc: /* USP 401 */

2013-08-15T17:13:58Z

‎USP 401

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-[[Archivo:ESTER.jpg|680x680px|centro|]]
+[[File:ESTER.jpg|680x680px|centro|]]
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 Place 1.5 g to 2 g of the substance in a tared, 250 mL flasks, add 20 mL to 30 mL of neutralized alcohol and shake. Add 1 mL of phenolphthalein, and titrate with 0.5 N alcoholic potassium hydroxide until the free acid is neutralized. Add 25.0 mL of 0.5N alcoholic potassium hydroxide. Heat the flask on a steam bath, under a suitable condenser to maintain reflux for 30 minutes, frequently rotating the contents titrate the excess potassium hydroxide with 0.5 N hydrochloric acid. Perform a blank determination under the same conditions. Calculate the ester value by the formula:
-[[Archivo:Ester value1.jpg|280x280px|centro|]]
+[[File:Ester value1.jpg|280x280px|centro|]]
 BHCl: is the volume in mL, of the hydrochloric acid consumed by the blank
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 It is possible to perform this test using the sample at the end of determination of [[acid value]], adding 15 mL of potassium hydroxide 0.5 N and heat the flask under a suitable condenser to maintain reflux for 3-4 h. Titrate the excess potassium hydroxide with 0.5 N hydrochloric acid (until the sample turns white). Perform a blank determination under the same conditions. Register the volume of hydrochloric acid consumed for the sample as the well blank. Calculate ester value by the formula:
-[[Archivo:Estervalue.jpg|280x280px|centro|]]
+[[File:Estervalue.jpg|280x280px|centro|]]
 BHCl: is the volume in mL, of the hydrochloric acid consumed by the blank

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 W: is the weight, in g, of the sample taken
-=Referencia=
 <references />

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 It is possible to perform this test using the sample at the end of determination of [[acid value]], adding 15 mL of potassium hydroxide 0.5 N and heat the flask under a suitable condenser to maintain reflux for 3-4 h. Titrate the excess potassium hydroxide with 0.5 N hydrochloric acid (until the sample turns white). Perform a blank determination under the same conditions. Register the volume of hydrochloric acid consumed for the sample as the well blank. Calculate ester value by the formula:
-[[Archivo:Estervalue.jpg|480x580px|centro|]]
+[[Archivo:Estervalue.jpg|280x280px|centro|]]
 BHCl: is the volume in mL, of the hydrochloric acid consumed by the blank

← Older revision		Revision as of 22:31, 15 August 2013
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−	[[Archivo:ESTER.jpg\|~~380x380px~~\|centro\|]]	+	[[Archivo:ESTER.jpg\|680x680px\|centro\|]]

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 In  ester value determination, the sample is hydrolysed to alcohol and using excess of standar potassium hydroxide solution. The excess of alkali is back titrated.
 USP-NF monographs presents a general procedure of ester value apply to fats, fixed oils and waxes.
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 It is possible to perform this test using the sample at the end of determination of [[acid value]], adding 15 mL of potassium hydroxide 0.5 N and heat the flask under a suitable condenser to maintain reflux for 3-4 h. Titrate the excess potassium hydroxide with 0.5 N hydrochloric acid (until the sample turns white). Perform a blank determination under the same conditions. Register the volume of hydrochloric acid consumed for the sample as the well blank. Calculate ester value by the formula:
-[[Archivo:Estervalue.jpg|280x280px|centro|]]
+[[Archivo:Estervalue.jpg|480x580px|centro|]]
 BHCl: is the volume in mL, of the hydrochloric acid consumed by the blank
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 W: is the weight, in g, of the sample taken
 =Referencia=
 <references />

← Older revision		Revision as of 17:17, 15 August 2013
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	Wax esters are oxoesters of long-chain fatty acids esterified with long-chain alcohols. The ester value shows the amount alkali consumed in the saponification of the esters<ref>Pharmacopedia/National Formulary. US., Vol. 1, 2009, p. 150</ref> and is possible identify and differentiate the waxes with this value; for example beeswax ester value is 72 to 79 mg KOH/ g, candelilla wax ester value is 31 to 43 mg KOH/g and carnauba wax ester value is 74 to 78 mg KOH/g.		Wax esters are oxoesters of long-chain fatty acids esterified with long-chain alcohols. The ester value shows the amount alkali consumed in the saponification of the esters<ref>Pharmacopedia/National Formulary. US., Vol. 1, 2009, p. 150</ref> and is possible identify and differentiate the waxes with this value; for example beeswax ester value is 72 to 79 mg KOH/ g, candelilla wax ester value is 31 to 43 mg KOH/g and carnauba wax ester value is 74 to 78 mg KOH/g.
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	W: is the weight, in g, of the sample taken		W: is the weight, in g, of the sample taken
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 ==USP 401==
 Place 1.5 g to 2 g of the substance in a tared, 250 mL flasks, add 20 mL to 30 mL of neutralized alcohol and shake. Add 1 mL of phenolphthalein, and titrate with 0.5 N alcoholic potassium hydroxide until the free acid is neutralized. Add 25.0 mL of 0.5N alcoholic potassium hydroxide. Heat the flask on a steam bath, under a suitable condenser to maintain reflux for 30 minutes, frequently rotating the contents titrate the excess potassium hydroxide with 0.5 N hydrochloric acid. Perform a blank determination under the same conditions. Calculate the ester value by the formula:
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 It is possible to perform this test using the sample at the end of determination of acid value, adding 15 mL of potassium hydroxide 0.5 N and heat the flask under a suitable condenser to maintain reflux for 3-4 h. Titrate the excess potassium hydroxide with 0.5 N hydrochloric acid (until the sample turns white). Perform a blank determination under the same conditions. Register the volume of hydrochloric acid consumed for the sample as the well blank. Calculate ester value by the formula:
 =Referencia=
 <references />