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The flow field-flow fractionation (FlFFF) analysis of a variety of neutral as well as ionic polysaccharides from plants and micro-organisms shows the generally broad distribution in molecular size of these polymers. This result is also obtained on a commercial sample of pullulan whose size distribution appears much wider than that of any of five standard fractions of the same polymer. Clear evidence of some physico-chemical properties of the polysaccharides is given by the study of the effect of the carrier ionic strength on salep, oxidized salep and konjac, carboxymethylcellulose and hyaluronic acid. While neutral polysaccharides, regardless of their origin, only slightly change size distribution in the presence of a simple electrolyte in solution, charged polymers, either naturally charged or chemically ionized, consistently exhibit very low retention levels in water which dramatically increase even at low salt concentrations. Exclusion mechanisms, including steric effects, are shown to be responsible for the anticipated retention times in water of these species that assume the expected statistical coil behavior only when electric charges are screened by the added electrolyte. Under these conditions, higher retention levels are obtained because the volume adjacent to the accumulation wall becomes more accessible to the sample during relaxation. On the basis of these findings, the elution behavior of a number of polysaccharide samples in-laboratory obtained from the fungus Aureobasidium pullulans under different incubation conditions is attributed to the presence of species varying in physico-chemical properties and molecular size.

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.

Glass and fused-silica capillary columns (100 μm I.D.) were precoated with a very thin layer of graphitized carbon black and then coated with polar liquid phases. The layer of graphitized carbon black and then coated with polar liquid phases. The layer of carbon black in the inner walls increased the wettability of the capillary columns and, consequently, a very uniform coating was obtained. The polymeric polar liquid phases were also more strongly retained on the carbon black, and these microcapillary columns showed a much higher temperature stability. Columns coated with free fatty acid phase, Carbowax 20M, 40M and 600M were prepared. The columns were tested with a mixture of polar compounds.

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.

The separation of the isotopic molecules C6H6-C6D6 and C7H8-C7D8 is reported. Reversed-phase liquid chromatography was used with a non-polar column and water-methanol mixtures as solvent, and separation factors higher than in gas chromatography were obtained. The operating conditions are examined and a procedure for optimizing the resolution between the two isotopic peaks is described.

Twelve phenolalkylamines normally used in different pharmaceutical products were determined in urine from volunteers given a therapeutical dose of the drug. The urine extracts were first derivatized with perfluoro propionic or butyric anhydride, then detected by capillary gas chromatography—negative chemical ionization mass spectrometry. The method is highly sensitive and specific in the analysis of biological samples.

The advantages of capillary columns connected in series for solving analytical probles are discussed. Two columns of the same length and very different polarity (SE-54 and PEG 20M) were used. Under isothermal conditions, owing to the carrier gas compressibility a noticeable increase in polarity is observed when the sequence of columns SE-54—PEG 20M is reversed. With temperature programming, an increase in the programming rate decreases the influence of the second column. By changing the programming rate during the analysis it is possible to optimize the column polarity to obtain the best separations. An application to the analysis of lemon oil is reported; complete separation of the most important components was achieved.

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.

A procedure is described for the detection of anabolic steroids in urine by using capillary gas chromatography—mass spectrometry. The method is suitable for doping control and has a sensitivity as low as 1 ppb. The excretion mode and the metabolism of ten commercial anabolic steroids is reported.

A general procedure is presented which allows the prediction of gas—liquid chromatographic behavior and the separation of complex barbiturate mixtures. Using E 301 and FFAP, binary stationary-phase columns were obtained that separated a complex mixture of barbiturates selected on the basis of the their frequency. The barbiturates were analysed in the free form using nitrogen saturated with formic acid vapour as the carrier gas at room temperature.

Mineral waters can be characterized by high-performance liquid chromatographie analysis after an on-line trace enrichment of the organic fraction. The major components of these non-volatile organic substances are the humic compounds found at a wide range of concentration. Phenylindole has been identified and determined in mineral waters stored in plastic containers.

A procedure is reported for the determination in natural waters of the six polycyclic aromatic hydrocarbons (PAHs) listed by WHO as indicators of pollution. The method consists in continuous liquid—liquid extraction, separation of the PAH fraction by thin-layer chromatography and reversed-phase high-performance liquid chromatography with a spectrofluorimetric detector. The method has been applied to unfiltered samples of river and sea waters with PAH levels below 0.1 ng/l.

A procedure is described for the determination of polynuclear aromatic hydrocarbons (PAHs) in petroleum oils, involving extraction of the sample, dissolved in cyclohexane, with N-methylpyrrolidone—water—phosphoric acid, separation of the PAH fraction from the total extract by thin-layer chromatography and an analysis by gas chromatography or gas chromatography—mass spectrometry with selected ion monitoring. The determination of some PAHs in a lubricating and in fuel oil is reported.

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.

The separation of benzene and perdeuterobenzene by gas—liquid chromatography has been investigated on glass capillary columns. The nature of the liquid phase plays a very important role in the separation of isotopically substituted molecules, the less polar (squalene) being more effective than silicone oil. With the former, the separation is better than expected on account of the differences of vapour pressure the reverse is found with latter phase. The thermodynamic of the chromatograhic process have been studied, and the difference of ΔG, ΔH and ΔS for both substances together with the ratio of the activity coefficients on squalene and silicone oil have been calculated.

The separation and identification of oxygen-containing terpenes can be performed by gas chromatography. The operating temperature should be low (

Complexes of n-nonyl-β-diketones with copper, nickel, aluminium, beryllium and zinc have been prepared and used as liquid phases in packed columns (20% on celite) for gas chromatography. They have a rather low melting point and a low vapour pressure. A series of retention volumes have been measured for homologous series of various compounds (alkanes, aromatic hydrocarbons, ketones, and alcohols) and these values have been compared with the retention volumes obtained on a conventional squalene column. The differences of thermodynamic functions have been determined and the retardation effect taken as a measurement of the interaction between the various compounds and the metal complexes. Particularly strong interaction has been found between the alcohols (especially the primary) and the n-nonyl-β-diketone nickel complex.

The separation of various isotopic molecules with deuterium substitutions is reported. Columns with porous polymer beads (Porapak Q) are employed. A comparison is made between this packing material and other adsorbents, as graphitized carbon black or silica gel. High separation factors are obtained. The working temperatures are usually higher with respect to the other materials, but the isotopic effects measured with the Porapak are more favourable for many of these separations.

Polynuclear hydrocarbons contained in the atmospheric dust are analyzed by a combination of thin-layer and gas chromatography. The dust as such, or a cyclohexane extract, is applied on a silica gel plate and developed with cyclohexanebenzene (1:1.5). In this way polynuclear hydrocarbons are separated from other classes of components such as paraffins, heterocyclics, etc. The part containing polynuclear hydrocarbon is extracted again and examined by gas chromatography on a glass capillary column.