INSIGHT INTO BASELINE TROUBLES AND PROBLEM RESOLUTIONS IN HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

For pharmaceutical industry, HPLC is more than 40 years old. Even after instrumental advancements in HPLC problems still arise, troubleshooting still comes. HPLC is the main stay of analytical section nowadays in pharmaceutical industry whether it is API industry or formulation plant. Best approach for troubleshooting HPLC problems is going with systematic way. At the start of quantitative chromatographic analysis, the first parameter of paramount importance is baseline, especially for measuring the area of any given peak. Baseline usually suffers from these errors, namely, high baseline drift, periodic baseline fluctuation, and spikes. This article aims at suggesting some working methodologies which will resolve as well as avoid cases of such errors and failures.

Analysis of lipophilic fraction from leaves, inflorescences and rhizomes of Silphium perfoliatum L.

This paper presents a qualitative and quantitative chromatographic analysis (GC/MS) of the lipophilic fraction extracted from leaves, inflorescences and rhizomes of <em>Silphium perfoliatum</em> L. collected in 1998-2000. It was shown that the extracts of leaves and inflorescences are similar in composition, containing among their main constituents: α-amyrine (up to 13.9% of total components in leaves, up to 11.3% in inflorescences), heptacosane (up to 7.1% in leaves, up to 7.6% in inflorescences), stigmasterol (up to 8.1% in leaves, up to 2.2% in inflorescences), γ-sitosterol (up to 6.9% in leaves, up to 2.2% in inflorescences), β-amyrine (up to 4.1% in leaves, up to 5.8% in inflorescences), β-caryophyllene (up to 2.6% in leaves, up to 1.5% in inflorescences), caryophyllene oxide (up to 4.4% in leaves, up to 2.9% in inflorescences), germacrene D (up to 13.8% in leaves, up to 9.7% in inflorescences) and α-pinene (up to 3.3% in leaves, up to 2.4% in inflorescences). The chemical composition of lipophilic extract of rhizomes significantly differs from that of leaves and inflorescences. The following compounds can be counted among the dominant ones occurring in rhizome extracts: diterpene of labdane type - 16-acetoxycarterochaetol (up to 45%) and sesquiterpenes - 7-b-H-silphiperfol-5-ene (up to 9.1%), 7-a-H-silphiperfol-5-ene (up to 10.7%), d-elemene (up to 7.6%), isocomene (up to 5.6%), germacrene D (up to 5.2%) and modhephene (up to 5.1%).