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Potteries are traditionally used for cooking and storing foods in Turkey, the Mediterranean, and Middle East regions. Leaching of inorganic arsenic into the traditional white bean dish cooked in pottery has been determined for the first time in the literature. Accuracy of this method was validated by the analysis of a certified reference material, commercially marketed standard solutions, and arsenic spiked solutions. Locally available potteries were examined for the leaching studies. Variation in the leachability of inorganic arsenic from the potteries by acetic acid versus the number of use was studied. The concentrations of arsenic leached by 4% acetic acid decreased by the usage number. The glazed potteries released arsenic at lower concentrations to leaching by acetic acid than the same group of nonglazed potteries. The concentrations of leached arsenic were relatively high in the white bean dish, where the leach of arsenic from the potteries to acetic acid was low. All of the potteries examined released inorganic arsenic to white bean dish in concentrations that exceed the daily BMDL 0.5 (210 μg/day). However, because the potteries are used only about once a month, direct application of the daily dietary intake limits is not appropriate. According to the weekly BMDL 0.5 , the estimated contribution from arsenic was in the range of 34–79% of BMDL 0.5 . The results of this study showed that the potteries are the potential sources of arsenic. Pottery oiling in ovens, which is another traditional procedure before using the potteries, reduced the leaching of arsenic to foods.

Arsenic in drinking water is a serious problem for human health. Since the toxicity of arsenic species As(III) and As(V) is different, it is important to determine the concentrations separately. Therefore, it is necessary to develop an accurate and sensitive method for the speciation of arsenic. It was intended with this work to determine the concentrations of arsenic species in water samples collected from Izmir, Manisa and nearby areas. A batch type hydride generation atomic absorption spectrometer was used. As(V) gave no signal under the optimal measurement conditions of As(III). A certified reference drinking water was analyzed by the method and the results showed excellent agreement with the reported values. The procedure was applied to 34 water samples. Eleven tap water, two spring water, 19 artesian well water and two thermal water samples were analyzed under the optimal conditions.

Removal of As(III) and As(V) species using ferric hydroxide supported on silica gel was studied. Laboratory reagent quality silica gel was used as to avoid uncertainties that may be caused by impurities. Ferric hydroxide precipitation was realized at various pH values and a relatively low pH 6.0 was chosen because, at this pH, the highest arsenic removal capacity and removal efficiency were obtained and clear supernatant solution was observed. It was also shown by arsenic speciation analysis at trace level that As(III) is adsorbed onto ferric hydroxide partly without oxidation to As(V); this has been a controversial point in the literature. The effects on arsenic removal of some parameters such as pH, flow rate and matrix ions were investigated. In the batch method, initial pH change of the solution did not significantly affect the arsenic removal efficiencies for As(III) and As(V) in the pH range of 3.1-9.7. This was attributed to the decreases of the initial pH values to around 5 at equilibrium. The column capacities of 1.32 mg As(III)/g sorbent and 1.21 mg As(V)/g sorbent were found for initial concentration of 1.00 mg/L arsenic. Batch capacities were 16.2 mg As(III)/g sorbent and 17.7 mg As(V)/g sorbent for initial arsenic concentration of 100 mg/L. The method was applied successfully to the removal of As(III) and As(V) from drinking water, geothermal water and mineral water.

The application of the recently introduced ethylchloroformate derivatization method for the separation and determination of selenomethionine and selenocystein in selenium-enriched yeast and yeast-free tablets by means of a gas chromatography–mass spectrometry (GC–MS) system has been studied. The efficiency of three methods for the extraction of selenomethionine from the tablets were compared. Total selenium content of the same tablets were measured using inductively coupled plasma (ICP)-MS and it was found that in the selenized yeast tablets about 80% of the total selenium is present as selenomethionine. The results were in agreement with the values in the labels and with the literature. The accuracy of the total selenium analysis was controlled by the analysis of a reference material.

The interferences between arsenic and antimony on each other during the hydride generation atomic absorption spectrometry (HGAAS) determination of arsenic and antimony using a quartz tube atomizer (QTA) were examined. In order to eliminate or reduce such interferences by selective heat decomposition of arsine and stibine, a Pyrex adsorption U-tube trap containing glass wool was placed between the drying tube and the quartz tube atomizer. Although at 250 °C stibine decomposes and is held almost completely by the trap, arsine is also decomposed to an extent of 24% and, therefore, thermal decomposition is not useful to eliminate antimony interference on arsenic determination. The effect of coating the glass wool in the U-tube with antimony on the arsenic suppression of the antimony signal was studied. The results showed that the antimony coating in the U-tube could not hold arsenic effectively and its interference on the antimony signal could not be eliminated by this means. In the second part of the study, oxygen was supplied to the quartz tube atomizer during atomization in order to study the effect of supplying oxygen on the antimony signal and on the interference of arsenic in the antimony determination. Sensitivity was increased in the presence of oxygen and interferences of arsenic on antimony determination was decreased by about 10% when oxygen was supplied. It was also observed that the extent of interferences depended mainly on the interferent concentration rather than the analyte concentration.

Determination of the total amount of tin by molecular emission cavity analysis (MECA) after generation of stannane by means of reduction with sodium tetrahydroborate(III) and measuring the SnH emission within the flame-containing MECA cavity is described. The volatile hydrides of tin, germanium and arsenic were separated on a short gas chromatographic column. The calibration graph was linear over the range 5–250 ng Sn, and the detection limit ( S N = 21 ) was 5 ng Sn, and the relative standard deviation for the determination of 50 ng Sn was 2.8% (n = 8). The method was applied successfully to the determination of total tin in fish, canned soft drinks and sea sediment samples. Hydride generation recovery from soil sample solutions, however, was low.

The moss, Hypnum cupressiforme and bark of the pine, Pinus brutia have been used for passive monitoring of airborne heavy metal pollution by an iron-steel mill of an industrialised area of Izmir, Turkey. Six metals, lead (Pb), cadmium (Cd), zinc (Zn), chromium (Cr), manganese (Mn) and iron (Fe) have been monitored using atomic absorption spectrometry. Between 26.2.1992 and 13.8.1992 samples were taken on five occasions at a distance of 0.25, 1.0 and 2.5 km from the mill. The results show an accumulation of all six metals, with differences between the moss and bark samples and a decrease in concentration with distance from the mill. The arithmetic means of the measured heavy metal concentrations in the moss, Hypnum cupressiforme, were always much higher than those in the bark of the P. brutia, indicating that the moss H. cupressiforme is more suitable than the bark of P. brutia for use in monitoring heavy metal pollution. The results show that the study area, within 2.5 km from the iron-steel mill, is heavily polluted.

Glazed and non-glazed earthenware is traditionally and widely used in Turkey and most of the Mediterranean and the Middle East countries for cooking and conservation of foodstuff. Acid-leaching tests have been carried out to determine whether the use of glazed and non-glazed earthenware may constitute a human health hazard risk to the consumers. Earthenware was leached with 4% acetic acid and 1% citric acid solutions, and arsenic in the leachates was measured using hydride generation atomic absorption spectrometry. Arsenic concentrations in the leach solution of non-glazed potteries varied from 30.9 to 800 μg L⁻¹, while the glazed potteries varied generally from below the limit of detection (0.5 μg L⁻¹) to 30.6 μg L⁻¹, but in one poorly glazed series it reached to 110 μg L⁻¹. Therefore, the risk of arsenic poisoning by poorly glazed and non-glazed potteries is high enough to be of concern. It appears that this is the first study reporting arsenic release from earthenware into food.

Ammonium-, nitrite- and nitrate-nitrogen were determined by molecular emission cavity analysis using a cavity containing an entire flame. Ammonium-nitrogen was converted to ammonia by injection on to solid sodium hydroxide. The calibration graph was linear for 5–100 µg ml–1 of nitrogen when the ammonia generated was swept directly into the cavity and for 0.05–1.0 µg ml–1 of nitrogen when it was collected in a liquid nitrogen cold-trap. Concentrations of 1.5 and 0.01 µg ml–1 of nitrogen could be detected using the direct and cold-trap methods, respectively. Nitrite was determined after conversion to nitrogen monoxide by iodide. Nitrate was reduced to nitrite using a copperised cadmium column and then determined as nitrite. The calibration graphs for both anions were linear up to 7 µg ml–1 of nitrogen and 0.1 µg ml–1 of nitrogen could be detected. The methods were applied successfully to the determination of nitrite and nitrate in meat products, and nitrate-nitrogen in drinking water samples.

Arsenic (0.1–5 μg), antimony (1–40 μg), tin (0.5–10 μg) and germanium (0.2–10 μg) are determined simultaneously by reduction to their hydrides with sodium tetrahydroborate(III), followed by gas chromatographic separation on a column of 10% E-301 silicone gum rubber on Porapak Q, and measurement of the emissions at 490 nm in an oxygen/hydrogen flame within a cavity. Detection limits for 1-ml samples are 35 ng As, 400 ng Sb, 85 ng Sn and 100 ng Ge. A more sensitive determination of arsenic (0.05–3 μg) and antimony (0.1–5 μg) in binary mixtures is also described; the detection limits are 15 ng As and 40 ng Sb.

Molecular emission cavity analysis (MECA) is shown to be useful for selective detection of sulphur or phosphorus compounds at the nanogram level in g.l.c. effluents. Introduction of a small oxygen flow into the cavity allows many other elements (e.g. Si, As, Sb, N, C) to be detected. The detection of microgram amounts of silylated amino acids is possible by measuring their SiO emission in the cavity at 580 nm.

Selenium (0.02–2 ppm), after conversion to hydrogen selenide -with sodium tetrahydroborate, can be determined by molecular emission cavity analysis. The detection limit is 7 ng of selenium. The effects of 26 ions are reported. The depressive effects of arsenic and antimony can be removed by selective volatilisation, and the enhancing effects of tellurium and sulphite by addition of tellurium to standards and by oxidation to sulphate, respectively.