F. Coccioli

Determination of phenolic acids in wine by high-performance liquid chromatography with a microbore column

Abstract A method for the extraction and separation of the non-volatile phenolic acids of wine is described. The extracts are analysed by HPLC with a microbe column and UV detection. The free phenolic acids and depsides in different wine samples were identified and determined.

Separation and identification of free phenolic acids in wines by high-performance liquid chromatography

Abstract Free phenolic acids in Italian wines and a sherry were identified by high-performance liquid chromatography. The samples were concentrated and passed through a Sep-Pak C18 cartridge and the acids were recovered by elution with 2 ml of tetrahydrofuran. The separation was carried out by gradient elution on a reversed-phase column with methanol—water and phosphate buffer (pH 2.7). Detection was carried out 280 and 230 nm.

Capillary electrophoretic separation of phenolic acids

Phenolic acids such as syringic, p-coumaric, vanillic, caffeic, 3,4-dihydroxybenzoic and gallic acid, which are present in wines and other alcoholic drinks, were determined by capillary electrophoresis using an uncoated fused-silica capillary. The optimum conditions for their separation were investigated. Examples of electropherograms of phenolic acids contained in some Italian wines are reported.

ANALYSIS BY HPLC-MS/MS OF BIOPHENOLIC COMPONENTS IN OLIVES AND OILS

The aim of this work was to analyze by HPLC-MS-MS natural biophenolic compounds in complex natural samples like olives and olive oils. Eleven benzoic and cinnamic acids, vanillin and other eight biophenolic compounds were studied by liquid chromatography-atmospheric pressure ionization mass spectrometry/mass spectrometry with a Turbo Ion source in the negative mode. To confirm the specific presence, with great sensitivity, of such compounds in olive samples, in brine samples and in extravirgin olive oil the fragmentation of precursor ions into the product species acquisition was used in Multiple Reaction Monitoring (MRM) mode.

Characterization of some styrene-divinylbenzene sorbents for reversed-phase chromatography

Abstract The preparation and characterization of laboratory made polymeric columns of Chromosorb 101 and Porapak Q are described, with reference to a PRP-1 column packed under the same conditions. Column parameters such as permeability, efficiency and peak asymmetry factor were calculated. The swelling propensity of the materials was measured and the dependence of peak shape on the type of organic solvent used was investigated. The efficiencies of Chromosorb 101 and Porapak Q columns were satisfactory but the spherical material PRP-1 gave better results. Porapak Q exhibited very good physical properties such as high rigidity and permeability. The swelding of polymers in acetonitrile is higher than in methanol, so a better column performance is obtained when acetonitrile is employed as the eluent.

Analysis of lemon and bergamot essential oils by HPLC with microbore columns

SummarySome citrus essential oils were analyzed by HPLC with both microbore and standard columns in reversed and normal phase. Volatile and non-volatile fraction were investigated. In the non-volatile fraction some coumarins have been identified. Fractions are detected spectrophotometrically at 220 nm and 320 nm before and after evaporation of samples. Some components were also identified by LC/MS.

Determination of flumethasone in calf urine and serum by liquid chromatography-tandem mass spectrometry.

Corticosteroids can be illegally administered to cattle as growth promoting agents to improve meat production. We developed a liquid chromatography-atmospheric pressure ionization mass spectrometry-mass spectrometry (LC-MS-MS) method able to identify and quantify flumethasone, one of the most potent fluorinated synthetic corticosteroid, in serum and urine from treated calves. The analyte was purified from urine (conjugated and free, following enzymatic hydrolysis) and from serum by C18 solid-phase and liquid-liquid extractions, then analyzed by LC-MS-MS monitoring the product ions of an abundant precursor (SRM in negative ionization mode). Results on flumethasone residues in biological fluids in three calves treated at different levels are presented. This method allowed the detection of flumethasone in bovine urine and serum at the 30-pg/ml level.

High-performance liquid chromatography of cyclic β(1 → 2)-d-glucans (cyclosophoraoses) produced by rhizobium meliloti and rhizobium trifolii

Abstract A method for the identification of cyclic glucans (cycloamyloses and cyclosophoraoses) in terms of the glycosidic linkage type and of the degree of polymerization (DP) using a reversed-phase 5-μm amine bonded silica column is proposed. The dependence of the logarithm of the capacity factors (log k ′) on the DP and on the structure of the cyclic oligosaccharides is established by comparing the chromatographic behaviour of β(1 → 2)- d -glucans (cyclosophoraoses) from two different Rhizobium strains with that of cycloamyloses and of mono- and disaccharides. The determination of the DP of the cyclosophoraoses was achieved by high-performance liquid chromatography (HPLC) of the partial hydrolysates of three collected peaks. HPLC experiments using cyclosophoraoses from Rhizobium meliloti SU-47 and Rhizobium trifolii TA-1 demonstrate that such microbial carbohydrates are mixtures of cyclic glucans with DP ranging from 17 to more than 33, in different proportions depending upon the bacterial source.

Analysis of orange and mandarin essential oils by HPLC

SummaryThe analysis of orange and mandarin essential oils (nonvolatile fraction) was carried out by HPLC in normal and reverse phase modes with UV and spectrofluorimetric detection in series.For the identification of chromatographic peaks a preparative HPLC was used, the purified fractions were analyzed by GC-MS and by LC-MS. Some flavones were found in these oils.

Development and validation of an MEKC method for determination of nitrogen‐containing drugs in pharmaceutical preparations

A fast and accurate micellar electrokinetic capillary chromatography method was developed for quality control of pharmaceutical preparations containing cold remedies as acetaminophen, salicylamide, caffeine, phenylephrine, pseudoephedrine, norephedrine and chlorpheniramine. The method optimization was realized on a Beckman P/ACE System MDQ instrument. The baseline separation of seven analytes was performed in an uncoated fused silica capillary internal diameter (ID)=50 µm using tris‐borate (20 mM, pH=8.5) containing sodium dodecyl sulphate 30 mM BGE. On line‐UV detection at 214 nm was performed and the applied voltage was 10 kV. The operating temperature was 25°C. After experimental conditions optimization, the proposed method was validated. The evaluated parameters were: precision of migration time and of corrected peak area ratio, linearity range, limit of detection, limit of quantification, accuracy (recovery), ruggedness and applicability. The method was then successfully applied for the analysis of three pharmaceutical preparations containing some of the analytes listed before.