Formic acid often is used for the analysis of peptides in proteomic studies by HPLC-MS, due to Its volatility and reduced signal suppression. However, poorer chromatographic performance can be obtained in comparison with trifluoroacetic acid or nonvolatile phosphate buffers due to increased overload...
This paper describes the production of a universal buffer system which can be used for acidic, neutral and basic mobile phases in HPLC. The mixture of alkylamine and phosphoric acid diluted with water gives the possibility to carry out separations with basic buffers on reversed phase columns with...
Ammonium hydrogencarbonate was tested for a number of drug-like compounds analysed as mixtures, and data obtained were compared to those from the classical and MS-friendly buffers widely used by chromatographers: trifluoroacetic and formic acids. The results of this study revealed the suitability of...
A comparative study on the stability of silybin and that in silymarin in buffers and biological fluids. Drug Metab Lett. 2009;3:115-119. [Cited in This Article: 1] 23. Yanyu X, Yunmei S, Zhipeng C, Qineng P. The preparation of silybin-phospholipid complex and the study on its ...
In this installment of "LC Troubleshooting," Dwight Stoll discusses several essential principles related to when and why buffers are important, as well as practical factors, such as commonly used buffering agents, that are recommended for use with different types of detector...
performed as follows: increasing convertase concentrations (generating from 0.1 to 2.5 nmol of 7-amino-4-methylcoumarin from the fluorogenic substrate pERTKR-MCA) were incubated with 8 pmol of the 1-19 substrate for 1 h at 37°C in 100 μl of buffers identical to those used for gp160 ...
The ionic strengths of all the buffers were fixed at 0.1 M by adding the necessary amount of potassium chloride when necessary. The compositions of the solutions at equilibrium were solved by using the extended Debye–Hückel theory, which estimates the activity coefficients of the ions in the ...
Screeningforbasicdrugsinequineurineusingdirect-injection differential-gradientLC–LCcoupledtohybridtandemMS/MS ShawnM.R.Stanley ∗ ,HsiaoChingFoo TheSingaporeTurfClubLaboratory,SingaporeRaceCourse,1TurfClubAve,738078Singapore,Singapore Received7November2005;accepted10March2006 Availableonline17April2006 ...
for the above dosage forms. Potentially beneficial additives fall generally into the following classes: other matrix materials or diluents, surface active agents, drug complexing agents or solubilizers, fillers, disintegrants, binders, lubricants, and pH modifiers (e.g., acids, bases, or buffers)...
If necessary, the pH of the preparation may be adjusted with a suitable buffering agent; conveniently, TRIS (i.e.trihydroxymethylaminomethane), phosphate or acetate buffers can be used. A particularly preferred formulation for parenteral administration is one containing the compound of the invention...