Capillary zone electrophoresis and capillary electrophoresis-mass spectrometry for analyzing qualitative and quantitative variations in therapeutic albumin

The present study describes a reproducible and quantitative capillary zone electrophoresis (CZE) method, which leads to the separation of nine forms (native, oxidized and glycated) of human serum albumin (HSA). In an attempt to identify the different species separated by this CZE method, the capillary electrophoresis was coupled to mass spectrometry using a sheath liquid interface, an optimized capillary coating and a suitable CE running buffer. CE-MS analyses confirmed the heterogeneity of albumin preparation and revealed new truncated and modified forms such as Advanced Glycation End products (AGEs). Assignment of the CZE peaks was carried out using specific antibodies, carboxypeptidase A or sample reduction before or during the CE separation. Thus, five HSA forms were unambiguously identified. Using this CZE method several albumin batches produced by slightly different fractionation ways could be discriminated. Furthermore, analyses of HSA preparations marketed by five pharmaceutical industries revealed that two therapeutic albumins, including that marketed by LFB, contained the highest proportion of native form and lower levels of oxidized forms.     

HPLC analysis of kaempherol and quercetin derivatives isolated by different extraction techniques from plant matrix

Soxhlet extraction, ultrasound extraction, and accelerated solvent extraction (ASE), followed by RP-HPLC with a photodiode array detector was used for the determination of flavonoids in fruits of Peucedanum alsaticum. Three compounds were identified: a kaempherol derivative (astragalin), and two quercetin derivatives (quercitrin and hiperoside). The highest extraction yields of the selected compounds were obtained by use of exhaustive ASE.     

Wetting transition in polyolefin blends studied by profiling techniques

Based on segregation data, determined with profiling techniques, we analyze surface phase diagram of binary liquid mixtures composed of random olefinic copolymers. Blends with extended‐ and small‐critical point wetting regimes are discussed. First observation of wetting transition is presented. Surface enrichment‐depletion duality, a phenomenon prerequisite to the 2^nd order wetting transition, is described.