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gagandeepsingh ● 2008-06-28 15:27 (6569 d 19:14 ago) Posting: # 1981 Views: 4,008 |
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Dear members, i am working with ellagic acid in human blood. provide me any mehtodology for determination/refernce using lcms-ms Thanks gagandeeep singh |
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H_Rotter ★ Germany, 2008-06-28 19:35 (6569 d 15:06 ago) (edited on 2008-06-29 00:27) @ gagandeepsingh Posting: # 1983 Views: 3,038 |
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Dear Gagandeeep, You are missing a method, and I am missing one word, namely 'please'. The forum is not a freebie-self-service supermarket.  Hermann |
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gagandeepsingh ● 2008-07-04 15:50 (6563 d 18:52 ago) @ H_Rotter Posting: # 1998 Views: 3,138 |
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❝ You are missing a method, and I am missing one word, namely 'please'. ❝ The forum is not a freebie-self-service supermarket. Sorry, i suppose i have put my question in wrong way. please accept my apology. I am working with the development of ellagic acid in human blood using LC-MS/MS API 4000. Method is in the -ve mode. I am using Mobile phase 2% acetic acid in Methanol -90 parts, and 2% acetic acid in water-10 parts. I am facing problem in the recovery and extraction of ellagic acid. it is a weak acid. I have tried the follwoing: tried with 2% acetic acid in methanol 500µl as extraction solvent and then evaported it and finally reconstitued in 100µl of methanol. The height i am getthig for a 100ng/ml spiked conc. was 100. recovery is the issue in my estimation which is coming to 2%. Similarly i tried 200µl spiked conc. +100µl of 2% acetic acid in water and then tried to extract with LLE using diethyl ether and reconstituting with 100µl of methanol and obtained same height. So the real problem is with the recovery of ellagic acid. If i use a strong acid then there occurs protonation and subsequent precipitation of ellagic acid. Please pour in some suggestions regarding the recovery/extraction technique for ellaagic acid. thanks and regards, gagan |
Ing. Helmut Schütz