Tailing Factor in Chromatographic Peaks (USP)

Here we can measure peak asymmetry in one of two ways as shown here.
The Tailing Factor, measured at 5% of the peak height, is largely used in the pharmaceutical industry. The Asymmetry Factor measured at 10% of the peak height is most often used in non-pharmaceutical analyses.

In most cases, the Asymmetry Factor and Tailing Factor will be roughly the same (although rarely exactly equal). Values should normally fall between 1.0 and 1.5 for a new column and the conditions of the test chromatogram. Less symmetrical peaks are often observed under actual running conditions with "real" samples, but any increase in peak tailing is a symptom of a problem that should be fixed.

http://www.chem.agilent.com/Library/Support/Documents/a10424.pdf

Analysis of Yohimbine HCl ( USP)

Yohimbine Hydrochloride

C21H26N2O3. HCl

Chromatographic Assay:
Mobile Phase:Prepare a mixture of H2O, Dibasic Sodium Phosphate Dihydrate (11.88g/L), and Monobasic Potassium Phosphate Solution (9.08g/L) (355:100:50). Add 4 g of Sodium Dodecyl Sulfate and mix. Add 285 ml of ACN, and mix.
Standard Preparation: USP Yohimbine HCl in MeOH to obtain a solution having a known concentration of about 0.2 mg/ml.
Assay Preparation: Transfer about 50 mg of Yohimbine HCl in 100-mL volumetric flask, dilute with MeOH to Volumn and mix. Transfer 10.0 mL of this stock solution to 25-mL Volumetric flask, dilute with MeOH.
System Suitability Solution: Quantitatively dilute an accurately measured volume of the standard preparation to obtain a solution having a concerntration of .40 ug Yohimbine HCl RS Per ml.
Chromatographic System: C8, 4.6 mm X 150 mm, Detector wavelength 229 nm, tailing factor is NMT 2.5, RSD is NMT 1.0%.

PS: Adapted from U.S. Pharmacopeia / National Formulary， USP30-NF25

Problem: CHEMStation could not connect the MSD

Check the computer, power of MSD, could not fix the problem, even reinstall the ChemStation Software, the problem remains...

Oh, the problem maybe be lie in IO-auto config

Here are some steps how to fix that:
(1) go to program, then agilent IO libraries-------IO config

(2) Follow the instructions, highlight the ASRL1、USB0, then select "romove", Only leave the TCPIP0.

That is it......








PS: if want to install the NIST Mass Spetral Library again, then need to