Count of the Waters

One of the uses of mains water is for washing chemicals used in pharmaceutical preparations to remove impurities or imwanted by-products of a reaction, and although the bacterial count of the water may be low, the volume used is large and the material being washed may be exposed to a considerable number of bacteria. 

Pooled 0- to 24-h and 0- to 168-h human urine samples were concentrated on an Oasis HLB 3.0-ml cartridges. The cartridge was loaded with pooled urine (3 ml) and washed sequentially with water containing 0.1 % acetic acid (2x3 ml, pH 3.2) and methanol (2x3 ml). Liquid scintillation counting of the water and the methanol extracts showed quantitative recovery of radioactivity in the methanol fractions. The methanol extracts were combined, evaporated to dryness under a stream of nitrogen, and dissolved in HPLC mobile phase. 

Two linear columns from Showa Denko, Shodex SB-806M and Shodex SB-806MHQ, and two linear columns from TosoHaas, TSK GM-PWxl and TSK GM-PW, were evaluated. Prior to the evaluation, the number of theoretical plates for Shodex SB-806MHQ, SB-806M, PWxl, and PW was determined to be 15,100, 15,700, 11,390, and 4710, respectively, as per manufacturer inspection. The lower plate count of the TSK PW column is due to the larger particle size of this column. Two mobile phases, water with 0.1 M LiNOi and 50 50 methanol/water (v/v) with 0.1 M LiNOi, were used for each of the four columns. These four columns were new and only PEO and PVP were analyzed with these columns in this study. Waters Ultrahydrogel columns have also been used in this laboratory. However, Ultrahydrogel columns are exactly the same as the TSK GM-PWxl columns based on the calibrations curves supplied by the manufacturers and by the pyrolysis GC data discussed later. 

The microbial count of the mains water will be reflected in both softened and deionized water which m be prepared from it. 

To study the absorption of cis-chlordane by bluegill and Xenopus, the exposure was made to 5 ppb of insecticide. The biomass and volume was one 5-g fish/6L and three 27-g Xenopus/8L in 10-liter glass cylinders. The aeration of the water was kept to the minimum and the containers were covered with aluminum foil to reduce loss due to volatilization. The radioactivity in control water without animals and in water with fish was monitored by counting 5 ml of water in 15 ml of Instagel (Packard Instruments) (16). 

Degradation of Trifluralin in Water. The amount of 14c recovered from water with time is shown in Table IV. About half of the total 14c (direct count analysis) in water was recovered by extracting twice with ethyl acetate hexane (7 3), indicating that polar metabolites rapidly formed. Also, the concentration of 14c in water increased most rapidly during the first 22 days, after which the rate decreased. Analysis of the water extracts by TLC is shown in Table V. Trifluralin disappeared very rapidly, decreasing to nondetectable levels between 9 and 22 days. Even as early as 2 days only 46% of the recovered 14C was trifluralin. 

IL). Initial experiments showed that uptake was complete within 2 hours. At the end of 2 hours (uptake) the mussels were rinsed, antipyrine solution was replaced with fresh Instant 0ceanR, and sampling at intervals continued. Portions of the water were also analyzed for antipyrine and metabolites. Data expressed in counts per minute per 1.0 ml were used to represent uptake and elimination of antipyrine. Experiments were routinely done in triplicate. 

The situation is quite different in the case of an acetic acid-water system. The energy of acetic acid adsorption on platinum is low and therefore the voltammetric curves taken in the absence and in the presence of acetic acid in the supporting electrolyte are nearly the same. However, radiometric data show that C-labeled acetic acid is adsorbed on the electrode surface. Most likely the acetic acid molecules are adsorbed on the top of the water molecules populating the electrode surface. Simultaneously recorded voltammetric and counting rate data are shown in Fig. 8. 

In one of his experiments, Perrin [6] counted a total of 13,000 particles of gamboge and found average concentrations proportional to the numbers listed in Table 21.1 at the given heights (h) above the bottom of the vessel. The experiment was carried out at 298 K, and the density of the particles was 0.2067 kg dm greater than that of the water in which they were suspended. The mean radius of the particles was 2.12 x 10 m. Calculate Avogadro s constant from these data. 

Karpas et al. reported on the determination of the 234U/238U isotope ratio (54.9 x 10-6) by MC-ICP-MS and ICP-QMS compared to a-spectrometry in hair, nail and water samples.46 A correlation of 0.99 was found between the two ICP-MS methods and of 0.98 with a-spectrometry for the water sample. The measurement time of the water sample after dilution for ICP-MS was 1 min and 1000 min (including uranium separation and counting time) for a-spectrometry.46... 

The aggregation of the silica species in solution continues upon dilution with water [3], With TPA, the main final products at room temperature are nanoslabs (8), counting 396 Si atoms and composed of twelve precursors (5) (Fig.l). With TPA, it was experienced that the timing of the water addition was not very critical. The yield of Silicalite-1 nanoslabs on silica basis is typically 80% [1]. With TBA, there is a violent hydrolysis and gel formation when the water is added from the beginning. To avoid this, it is preferred to add water after complete hydrolysis. The MEL nanoslabs with occluded TBA rapidly dimerize at room temperature to result in the formation of slabs with dimensions of 1.3 x 4.0 x 8.0 nm [3], The product yield on silica basis is similar to the TPA system. With TEA, the amount of extractable silicate was much smaller. 1R spectra of the extracts recorded after 24 h stirring of the solutions are shown in Fig.3. 

Another approach employs the catalytic combustion of organics over heated copper oxide. The C02 formed in the process was suitable for counting. Passing the water formed in the com-... 

After both sets of experiments were completed, the ground-water was drained from the cells and selective chemical extractions of the granite cell walls were performed. The cells were filled with 0.5 mol/L CaCl solution and stirred continuously for 72 h to displace exchangeable radionuclides. After a rinse with demineralized water to remove residual CaCl- solution, the cells were filled with KTOX solution and stirred ror 24 h to remove radionuclides associated with oxyhydroxides. All solutions were analyzed by gamma spectrometry to determine the amounts of radionuclides extracted. Residual activity was measured by direct gamma counting of the cells. 

Eluates can be analyzed with an on-line radiodetector or can be collected in fractions (0.5 mL) and quantitated by 3-scintillation counting. Eluted peaks are compared to retention times for standards prepared from commercial [3H] phosphoinositides and [32P]-labeled D-3-phosphoinositides prepared as described in Subheading 3.2. An example of a typical HPLC separation of the water soluble deacylation products from [32P]Pi- labeled leukaemic cell line is shown in Fig. 2. 

Total Bacteria Count The TBC is determine by directly counting the actual number of microorganisms collected on a filter after it is used to filter a sample of the water in question.5 The sample is stained with acridine orange and viewed with an epi-illuminated fluorescent microscope. This technique is more accurate and quicker than the culture technique, but is not as practical for field work. 

This technique involves simultaneous counting of the number of impulses in the foam in an empty container and in a water solution container. The foam expansion ratio is calculated from the following formula... 

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