Rain water analysis

The minimum pH of rain water saturated with carbonic acid will be 5.5 to 5.6. In areas where the soil is calcareous, in case of a pollution of precipitation by dust raised by the winds, the pH will reach values somewhat above 7. From the ion balances of rain water samples preserved prior to 1930 (Tennessee), Cogbill has calculated that at that time the pH values were about 7.5. In glacier ice from the Cascade Mountains, minimum pH values of about 5.6 were found, which corresponded to the pH of water saturated with carbonic acid. Colllnson and Menschlng, performing rain water analysis (1919 -... 

This experiment describes a method for determining the acidity, reported as an equivalent molarity of H2SO4, of rain water. Because the volume of standard base needed to titrate a sample of rain water is small, the analysis is done by a standard addition. A 10.00-mL sample of nominally 0.005 M H2SO4 is diluted with 100.0 mL of distilled water and standardized by titrating with 0.0100 M NaOH. A second 10.00-mL sample of the sulfuric acid is mixed with 100.0 mL of rain water and titrated with the same solution of NaOH. The difference between the two equivalence point volumes... 

Figure 5.22. Voltammogram of the simultaneous determination of Cu, Pb, Cd, and Zn with DPASV at the HMDE, and subsequent determination of Selv by DPCSV in the same run in rain water at an adjusted pH of 2. Preconcentration time for DPASV 3 min at -1.2 V, for DPCSV 5 min at -0.2 V. 1 Original analyte. 2 After first standard addition. Total analysis time with two standards. Source Author s own files...

Because of its exceptional selectivity, sensitivity and speed, IC is particularly suited to applications involving analysis of anions and cations in wastewater, natural waters, source effluents, workplace environments, ambient air and rain water. The analysis of organic as well as inorganic ions can be performed by 1C. Table I is a growing list of ions which have been successfully separated and detected. The principles of IC and selected applications to environmental pollutants are described in this paper. 

Carlson, et al (4) and C. Anderson, et al (5) have shown IC to be an excellent technique for low ppb analysis of water. Environmental applications for these analyses include determination of rain water composition and analysis of fuel cell effluents because ions in these solutions are often present in low ppb concentrations. Concentrator columns (3 x 50 mm) are used to accumulate sample ions to detectable quantities as large sample volumes are pumped through them. Samples may vary from 1 to 100... 

A CE determination of fluoride in rain water was compared with IC and ISE potentiometry the IC response was related to the total concentration, whereas CE and ISE responded to free fluoride [50]. The fluoride concentrations obtained by CE and ISE were systematically lower than those obtained by IC due to the fluoride complexation with aluminium. The detection limits for IC and ISE were similar (0.2 and 0.3 pmol/l) and somewhat lower than those for CE (0.6 xmol/l). CE was evaluated as an alternative method to the EPA ion chromatographic method for the determination of anions in water and a better resolution and a shorter analysis time were found for CE [51]. 

Rains C. 1982. Atomic absorption spectrometry. In Minear RA, Keith LH, ed. Water analysis. Vol. II. Inorganic species. Part 2. New York, NY Academic Press, 235-273. 

Simultaneous analysis of both anions and cations indicates that water samples from various localities contain many of the same ions but in differing amounts. Fig. 2.24 illustrates typical chromatograms of tap water and rain water. 

Sulfite and bisulfite in rain water are rapidly oxidized to sulfate by the catalytic effect of metallic ions such as Fe(III) and Mn(II). The rates of oxidation of S(IV) in test solutions were measured using ion chromatography. The rate constant, k, measured for a 12.5 yM S(IV) solution was found to be 0.6-10.4 hr 1 at pH 3-6 in the presence of 1.8-yM Fe(III) and 0.18 yM Mn(II) catalysts, and 0.4-5.9 x 10 J hr 1 without the catalysts. Triethanolamine (TEA) was used to stabilize actual rain water samples prior to analysis. 

The oxidation of S(IV) is a first order reaction with respect to S(IV) (2,3). This reaction is accelerated by the presence of metallic ions such as ferric and manganous ions which act as catalysts (4-8). Therefore, the effect of the metallic ions on the oxidation of S(IV) was investigated by using test solutions. Table I shows experimental conditions for the oxidation of S(IV) in test solutions. The pH values of synthetic rain water samples were adjusted between 3 and 6. S(IV) concentration in the test solutions was adjusted to 12.5 yM most of S(IV) existed as bisulfite at pH 3-6 (9). The rate of S(IV) oxidation was measured using ion chromatographic analysis. The pH of each test solution was adjusted by using a buffer. 

In order to determine S(IV) in rain water, it is necessary to prevent the oxidation of S(IV) between sampling and analysis. The suppressive effect on the oxidation of S(IV) was investigated by the addition of EDTA (Ethylenediaminetetraacetate) or TEA (Triethanolamine) as masking reagents for FeJ+ and Mn. Table III shows the suppressive effect of EDTA or TEA at various pH values. The suppressive effect was not observed between pH 3 and 5, because neither EDTA nor TEA chelate with Fe3+ and Mnz+ at these pH values. EDTA and TEA were found to be very effective for the suppression of the oxidation of S(IV) in solutions having neutral and basic pH values. 

Analysis of rain water (Experiment 50) Effect of heavy metal salts on the activity of enzymes (Experiment 56)... 

Colorimetric methods Silicon is determined by the molybdenum blue spectrophotometric method after solubilization in H2O, in alkaline solutions or in concentrated HF. A flow analysis procedure for the measurement of soluble silicon with respect to the total Si concentration is used. The proposed method is applied to samples of rain water and of aerosols on filters [45]. Simultaneous determination of orthophosphate and silicate in brackish water is performed by the same technique. Molybdate/ antimony, ascorbic acid, and oxalic acid reagents are added to the samples and spectra are recorded in the wavelength range 410-820 nm after a total reaction time of 30 min [46]. 

Until recently very little research work had been carried out to determine the relationship between plant cover in the area and the regional or global characteristics of the atmosphere. Our work has been developed in the Amazon region and we have tried to establish the relationship between the present climate equilibrium and the dense forest cover which extends over an area of more than 5 million km The research was carried out in successive stages, involving analysis of surface meteorological data, radiosonde data, satellite photographs, and analysis of chemical and isotope composition of rain water. 

Fallout, rain water, dust Monthly Nuclide analysis Basin method... 

Fig. 8-5. Anion analysis of rain water. - Separator column IonPac AS4 eluent 0.0028 mol/L...

Figure 14.3 shows the ion chromatographic separation of anions in rain water and Figure 14.4 represents the analysis of organic acids and inorganic anions in wine. 

J. Slanina, F. Bakker, A. Bruyn-Hes, J.J. Mols, Computer-controlled multichannel continuous-flow analysis system applied to the measurement of nitrate, chloride and ammonium ions in small samples of rain water, Anal. Chim. Acta 113 (1980) 331. 

Saefudin A., 1997. Analysis of rain water at EMC station Serpong, Indonesia, paper presented at the 4th ASEAN Workshop on Air Quality Monitoring and Analysis with Emphasis on Acid Deposition, Technopolis, Pathumthani, Thailand, 25 Febmary-4 March 1997. 

Stripping voltammetric methods have phenomenal detection limits (below 100 ppt) for metals Zn, Cd, Pb, Bi, Cu, Sn, Tl, As, Se. The precision in pure solutions is 5-10%. Time for complete (six to eight elements) determination is up to 40 min. The method is an absolute favourite in the analysis of marine and river waters, rain and snow (Golimovsky et al., 1985 Nuernberg, 1985 Van den Berg, 1986 Donat and Bruland, 1988). The determination is independent of salt content Therefore the technique is very useful in marine water analysis. For all other environmental samples where digestion is necessary (soil, plants, sediments, aerosols) the fantastic detection limits are reduced to the normal JLg/kg level (Adeluji et al., 1985 Ostapczuk et al., 1988). This is due to the necessity to obtain interference-free solutions and connected to the problem with reagent blanks. 

Schutyiser, P., 1978. Instrumental neutron activation analysis of dry atmospheric fall-out and rain water. Anal. Chim. Acta 100, 75-85. 

Practically all natural materials contain radioactive nuclides, though usually in such low concentrations that they can be detected only by very sensitive analysis. This is true for water (rain water, rivers, lakes, sea), rocks and soil, and all living matter, as well as for... 

The conventional analysis of Rain water is coprecipitation with barium sulfate... 

Kasahara M, Takahashi K, Sakisaka M, Tomita M (1993) Standard samples and calibration of PIXE analysis. Nucl Instrum Methods Phys Res B 75 136-139 Kasahara M, Ogiwara H, Yamamoto K (1996a) Soluble and insoluble components of air pollutants scavenged by rain water. Nucl Instrum Methods Phys Res B 118 400-402 Kasahara M, Park JH, Chatani S (1996b) Size distribution and solubility of 15 elements in atmospheric aerosols. Int J PIXE 6 299-310... 

Separation and detection methods for the specific and sensitive determination of hydroperoxides in laboratory experiments and in rain water must be developed. In addition, methods for the analysis of the whole product distribution were necessary. These methods should have been applied to the analysis of different reaction mixtures. 

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