Log in
Register|
chari ☆ 2007-12-20 16:24 (6759 d 09:48 ago) Posting: # 1406 Views: 5,018 |
|
|
Dear group members, I am developing the bioanalytical method for theophylline molecule on lc/ms/ms. I m facing problem with the peaks in blank plama. Even am getting 10 to 11 thousand area in blank. My mobile phase composition is ACN:0.1%HCOOH. flow rate adjusting from 0.8 to 1.0ml. pka of the molecule is 8.66. Am trying with different moble phase composition. My extraction method is LLE. Am using Tertiary butyl methyl ether (tried with diff solvents). only problem facing with the area in the blanks. Am not understanding why peaks are coming in the blank plasma. Am i following the correct method ? is there any method to over come peaks in blanks? pl suggest me the right way to develop my method. looking forward for your reply, regards chari -- Edit: Category changed. [HS] |
|
Helmut ★★★   Vienna, Austria, 2007-12-21 13:03 (6758 d 13:09 ago) @ chari Posting: # 1413 Views: 4,305 |
|
|
— Dif-tor heh smusma 🖖🏼 Довге життя Україна! ![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png) Helmut Schütz ![[image]](https://static.bebac.at/img/CC by.png) The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
|
sudheer ☆ 2009-08-28 12:59 (6142 d 14:13 ago) @ Helmut Posting: # 4133 Views: 3,396 |
|
|
You can try in Solid Phase Extraction. |
|
chiragkhatri ★ India, 2007-12-22 06:18 (6757 d 19:55 ago) @ chari Posting: # 1416 Views: 3,981 |
|
|
Dear Chari, There can be several reasons for the problem you have quoted. Try changing the grade of Formic acid to Sigm-aldrich or other similar and even of TBME or reduce the concentration of formic acid in mobile phase. Try to pickup another daughter ion (next highest intensity to the existing daughter ion) Evaporate TBME under nitrogen stream and reconstitute and inject, if you get peaks then probably your evaporator nozzles are contaminated. Hope this might help. Thanks Chirag |
Ing. Helmut Schütz