Comparison of accumulation capacities of two lichen species analyzed by instrumental neutron activation analysis

Instrumental neutron activation analysis and ICP-OES were used to determine 3 8 elements in two lichen species namely Xanthoria parietina (L.) Th. Fr. and Parmelia tiliacea (Hoffm) Ach. which were collected in Aegean Region of Turkey. It was found that the accumulation capacities of two species differed only for the elements Ca, Cl, Cu and Pb by using ANOVA at 95% confidence level. Average concentrations of all elements except for Ba, Mn and Hg were higher in Parmelia tiliacea. For the elements Ba, Br, Co, Cr, Cs, Fe, K, Mg, Mn, Mo, Rb, Sb and Ti, the equation y - ax+b could be used to make interchangeability possible between two species

Sampling and analysis of snow water: Experimental problems and interpretation of results

Sampling and analyses of snow water at a mountainous site of northwestern Turkey were described. A snow sampler designed in our laboratory was used in the sampling. Ion chromatography, flame atomic absorption and emission spectrophotometry were very good techniques for the determinations of major ions in snow samples. The accuracy of results was tested by using different standard reference materials for both techniques. The results were in good agreement with the certified concentrations. The results of analyses were accepted if the error was less than 15%. The overall precision was in between 1-6%. The concentrations of snow samples were high compared with the literature values. The pH of them was found to be acidic with the average value of 4.3. Magnesium had the highest average scavenging ratio, and ammonium ion had the lowest average scavenging ratio. Sodium, K, Ca and Mg were mostly originated from the earth crust. Marine contribution to the sampling site was also effective

Geographic patterns of elemental deposition in the Aegean region of Turkey indicated by the lichen, Xanthoria parietina (L.) Th. Fr.

Lichen samples from different parts of the world have been known to accumulate elements to a greater degree than higher plants, if they are exposed to these elements from the atmosphere or from water and sediments. It has been hypothesized that lichens can be used to monitor air pollution around point and area emission sources. Local variation (variation in substrate, age and morphology of lichen samples) of element concentrations would not be large enough to affect the concentration patterns in large areas. We tested this hypothesis in the Aegean region of Turkey, which is very urbanized and industrialized. No such study has been conducted before in this part of the country. A total of 234 samples of the lichen Xanthoria parietina were collected from a 51 800-km(2) area. Samples were washed and analyzed by INAA and ICP-AES for 35 elements. The range of the concentrations for most of the elements on a local scale was an order of magnitude lower than for the element concentrations on a regional scale. The mean local coefficient of variance (CV) was found to be 15, providing that the local variation did not affect the concentration of elements in the sampling region. According to cluster analysis, 8 (As, Hg, Pb, Sb, Fe, Mn, Na and K) elements are indicative of important local pollution locations and their zone of impact in the region. By mapping the concentrations of eight indicative elements in lichen Xanthoria parietina of the Aegean region, it was possible to relate deposition to the existence of known sources of pollution in certain areas. Location of pollution sources such as iron-steel plants, and coal burning in the cities, industrial activity and two important coal-fired power plants generally corresponded with locations of highest element accumulations in the lichens

Chemical characteristics of atmospheric aerosols in a rural site of northwestern Anatolia

Aerosol samples were collected daily at a rural mountainous site of northwestern Anatolia during September 1993-April 1994. Concentrations of SO42-, NO3-, Cl-, NH4+, Na+, K+, Ca2+ and Mg2+ have been determined. Sulfate made up the 30% analyzed aerosol mass with a 2.14 mu gm(-3) average concentration. Measured concentrations were comparable with other rural area data except Ca2+ which was higher in our station with an average concentration of 1.12 mu gm(-3). Monthly concentrations of major ions fluctuate depending on meteorological factors, seasons and source strengths. Saharan dust storms affected the sampling site especially in autumn and spring seasons. Wind sector analysis indicated that the most important source regions were located both to the south and north of the station. However, air masses from southerly direction at which a power plant is located have been concluded to bring the greatest amount of anthropogenic pollutants to the sampling site. (C) 1997 Elsevier Science Ltd

Determination of metal concentrations in lichen samples by inductively coupled plasma atomic emission spectroscopy technique after applying different digestion procedures

Three digestion procedures have been tested on lichen samples for application in the determination of major, minor and trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Ph, V and Zn) in lichen samples collected in Aegean Region of Turkey by inductively coupled plasma atomic emission spectrometer (ICP-AES). The acid mixture of concentrated HNO3, H2O2 and HF were used. The instrument was optimized using lichen matrix considering RF power, nebulizer pressure, auxiliary flow rate and Pump rate. The accuracy of the overall analyses was first estimated by analysis of two certified reference materials. Good agreement between measured and reference values were found for almost all elements. As the second way of determining the accuracy, results obtained from independent analytical techniques (ICP-AES and instrumental neutron activation analysis (INAA)) were compared for all elements by analyzing real samples. Correlation coefficients of two techniques for the elements ranged between 0.70 (Mg) and 0.96 (Fe). Among the three digestion systems, namely microwave, open vessel and acid bomb, microwave digestion system gave the best recovery results. The method detection limit (MDL) was computed Using reagent blanks of microwave digestion system since it provides cleaner sample preparation. Detection limit is adequate for all elements to determine the elements in lichen samples. The precision was assessed from the replicate analyses of reagent blanks of microwave digestion system and was found to be less than 1.5% relative standard deviation (R.S.D.)

Measurement of gas phase pollutants and aerosols at a mountainous site

Gas phase pollutants (O-3, NOx and SO2) suspended particulate matter (SPM), and major ions in aerosols were measured for 12 month period at a mountainous site of northwestern Turkey which is suffering from severe forest decline. Gaseous pollutants, SPM and meteorological parameters were measured in hourly basis with automated analyzers. Aerosol samples were collected daily. The long and short term trends in the concentrations of the measured parameters were investigated in order to understand the causes of the observed concentrations of these pollutants. Higher concentrations of O-3 during summer months were consistent with the higher photochemical production from precursor gases (NOx) with increased solar flux. The diurnal variations of O-3 and NO2 were 27 and 2.3 ppb respectively during summer. The diurnal pattern of O-3 NO, NO2 and SPM describes a photochemical smog scenario. Sulfate makes up about 30% of the total analyzed aerosol mass. A lower pH associated with a high level of SO42- and NO3- in aerosols is an indication of acid deposition. Wind sector analysis indicated the largely contributing source regions to be located in the southern and northern direction of the sampling site which is Bursa city, local industries and the nearby power plant

Determination of major and rare earth elements in bastnasite ores by ICP-AES

Analytical procedure for direct determination of La, Ce, Sm, Eu, Y, Yb, Pr, and Nd by ICP-AES in bastnasite ores without need for the initial separation or preconcentration of the rare earth elements (REEs), has been developed. Besides, rare earth elements, five major elements (Al, Ca, Ba, Fe, and Mg) were also measured. Two standard reference materials (GSP-2 and STM1 purchased from the U.S. Geological Survey) were selected to test the accuracy of the method. Good agreement was generally achieved. Based on these experiments it appeared that direct ICP-AES method should be attractive and well suited for the routine determination of REEs in rare earth ores

Characterization of aldrin epoxidation in flathead mullet (Mugil cephalus) liver microsomes: Involvement of CYP3A

Toxic organochlorine pesticides, aldrin and its metabolite dieldrin, have been reported to contaminate the aquatic environment highly. In the present study, epoxidation reaction of aldrin to dieldrin was studied in mullet liver microsomes and contribution of cytochrome P450 isozyme(s) was determined by using specific cytochrome P450 inhibitors and substrate. Flathead mullet samples (Mugil cephalus) were caught from the West Black Sea Region of Turkey. Fish liver microsomes were prepared by differential centrifugation. Epoxidation of aldrin to dieldrin was determined by measuring the amount of dieldrin produced using gas chromatography and electron capture detector. Aldrin epoxidation was linear with time up to 60 min and with protein concentration up to 10 mg/mL. Maximal fish liver aldrin epoxidase activity was observed at pH 7.6. Aldrin epoxidase exhibited monophasic kinetics with apparent Km value of 140 μM for aldrin. The enzyme activity was inhibited approximately by 9% and 16% by methanol and DMSO, respectively. On the other hand, aldrin epoxidation was enhanced by about 113% with 2% ethanol in the incubation medium. Ketoconazole (CYP3A inhibitor), potentially inhibited the metabolism of aldrin, tolbutamide (CYP2C substrate), and alpha-naphthoflavone (CYP1A inhibitor) did not show inhibition. The results of this study strongly suggest that CYP3A is the cytochrome P450 isozyme involved in aldrin epoxidation in mullet liver microsomes whereas CYP2C and CYP1A are not involved