On-line microdialysis-ion chromatographic determination of inorganic anions in olive-oil mill wastewater.

A fully automated method is presented for the determination of inorganic anions in olive-oil mill effluents using on-line dialysis-ion chromatography. The wastewater is first of all sonicated at room temperature to make it homogeneous, then diluted and microdialized. Most of the organic load of the effluents is removed in a few minutes without using reagents, while soluble anion quantitation remains unaffected. The clear solution is analyzed for the inorganic anions content by direct injection on to an ion chromatograph equipped with a conductivity detector. In the absence of standards, the separation efficiency of microdialysis has been investigated by spiking wastewater samples as well as standard oil emulsions with varying amounts of inorganic anions and subjecting them to microdialysis for different periods of time prior to performing instrumental analysis. Excellent spike recoveries and low relative standard deviations are obtained for all the anions if a 10 min microdialysis time is overcame. Chloride, nitrite, nitrate, phosphate and sulphate are not affected by the microdialysis procedure and their recovery is between 96 and 104% in wastewater as well as in standard oil emulsion. Calibration plots are linear over about two orders of magnitude. The dialysis membrane has been replaced after more than 100 analyses. The UV photolysis pre-treatment of the same sample evidences the different information that can be obtained by the two sample pre-treatment procedures.

Ion chromatographic determination of metals in biocompatibility testing.

The increasing numbers of materials used in surgical implants require a wide spectrum of tests to evaluate their biocompatibility. The release of metals is an important additional feature for determining the suitability for clinical applications of biomaterials such as ceramics and metals. Due to the difficulty of performing time-consuming experiments in vivo, one approach for rapidly determining the suitability of biomaterials and their interactions with the tissues with which they will come in contact is to perform in vitro tests, based on cell culture analysis, using solutions that reproduce the cleavage and binding capabilities of body fluids and tissues. The present work reports on the application of ion chromatography to the simultaneous determination of some metal ions in a few biologic media. Agar-Agar solution, "199 medium, " and betadine and Schiff's reagents were selected as some of the most representative biologic simulating solutions. A method is recommended for the pretreatment of the sample with minimal reagent addition since it is very rich in organic compounds and cannot be analyzed without pretreatment. The proposed procedure requires the sample to be subjected to oxidative UV photolysis for about 60 min in an UV digester at 85 degrees +/- 5 degrees C, followed by the ion chromatographic determination. Lead (II), cadmium (II), iron (III), copper (II), nickel (II), zinc (II), and cobalt (II) simultaneously were determined at microg/L levels.

Determination of transition metals in wine by IC, DPASV-DPCSV, and ZGFAAS coupled with UV photolysis.

In the present work ion chromatography (IC), differential pulse anodic (DPASV) or cathodic stripping voltammetry (DPCSV), and Zeeman graphite furnace atomic absorption spectroscopy (ZGFAAS) were applied to the determination of heavy and transition metals in wine. The matrix is degraded by oxidative UV photolysis in a digester equipped with a high-pressure mercury lamp. The temperature of the sample is maintained at 85 +/- 5 degrees C by a combined air/water cooling system. This procedure has decisive advantages if compared with other sample pretreatment techniques. Most organic wine constituents degrade in <1 h, whereas metals quantitation remains unaffected by UV radiation, with the exception of manganese. The clear solution is directly analyzed for most common heavy and transition metals such as cadmium, cobalt, copper, iron, lead, nickel, and zinc. In the absence of standards, the results obtained by different techniques are compared and are found in good agreement. All of the considered techniques appear to be equivalent, but ZGFAAS is more time-consuming because it does not permit multielement analyses.

State-of-the-art ion chromatographic determination of inorganic ions in food.

A review of the applications of ion chromatography (IC) to the determination of inorganic ions in food is presented. The most promising sample preparation techniques, such as accelerated solvent extraction, supercritical fluid extraction, solid-phase extraction, UV photolysis, microwave-oven digestion and pyrohydrolysis are discussed. Among the various inorganic anions, nitrogen, sulphur and phosphorus species and halides are widely determined in foods and to a lesser extent only, cyanide, carbonate, arsenic and selenium species are considered. IC determination of inorganic cations deals with ammonium ion, alkali, alkaline-earth, heavy and transition metals particularly and only a small amount of literature is found on the other ones, like aluminium and plantinum. A particular advantage of IC over traditional techniques is the simultaneous determination of several species.