Of solution samples

Atomization The most important difference between a spectrophotometer for atomic absorption and one for molecular absorption is the need to convert the analyte into a free atom. The process of converting an analyte in solid, liquid, or solution form to a free gaseous atom is called atomization. In most cases the sample containing the analyte undergoes some form of sample preparation that leaves the analyte in an organic or aqueous solution. For this reason, only the introduction of solution samples is considered in this text. Two general methods of atomization are used flame atomization and electrothermal atomization. A few elements are atomized using other methods. 

Three fly ash samples, Drax fresh, Drax weathered and Meaford weathered, in their natural moisture condition were lightly packed into acrylic columns (5 cm diameter, 40 cm long) to achieve a uniform bulk density, comparable to values in the literature (dry bulk density 1.01-1.43 mg/m3, Mattigod et al. 1990). Then, lOOOmL of deionized water were passed through each column at a flow rate of 25 mm/ day, and 50 mL of solution samples were collected every two days. 

Both of these in situ devices use substantially less solution (volumes of solution samples for each kinetic run are usually of the order of a few cm3) than a typical piston-cylinder apparatus. The pill-box cell method has the advantage that the cell can be filled in an appropriate glove box for oxygen-sensitive samples or for nonaqueous solvent-based systems that are sensitive to moisture. Temperature control is exerted by fluid circulating through the metal block. 

Produced HBr is scrubbed by the use of 10 N sodium hydroxide solution to form sodium bromide. For all the runs, the initial inventory is 1.25 L of sodium hydroxide solution. The NaOH solution was sampled at regular intervals and sent to Argonne s Analytical Chemistry Laboratory for analysis. Volume aliquots of solution samples were diluted with reagent water and analysed by ion chromatography to determine bromide. Separate aliquots were diluted with acid addition and analysed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) to determine calcium. During the data analysis, adjustments are made for the addition of condensed unreacted steam to the neutralisation solution. 

The disadvantage of solution sample preparation of oil samples for metal analysis is the loss of sensitivity due to the dilution factor and the effect the sample/solvent may... 

Schroeder AC, DiGiovanni JH, von Bredow J et al. (1989). Pralidoxime chloride stability-indicating assay and analysis of solution samples stored at room temperature for ten years. J Pharm Sci, 78, 132-136. 

Strictly speaking, the concentration measures per volume of solvent (Bunsen), per number of moles in the solution (mole fraction), and per mass of solution (samples) are not linearly related, and hence Henry s law cannot simultaneously be valid for all forms. To illustrate the problem, consider the conversion from mole fraction concentrations Xi to per weight concentrations Ci ... 

Yamiguchi H, Itoh S, Igarashi S, Naitoh K, Hasegawa R (1998) TXRF analysis of solution samples using polyester film as a disposable sample-carrier cover. Anal Sci 14 909-912 Yan B-D, Meilink SL, Warren GW, Wynblatt P (1987) Water absorption and surface conductivity measurements on alpha-alumina. IEEE Trans Components Hybrids Manufact Tech CHMT-10 247-251 Yashiro W, Ito Y, Takahasi M, Takahashi T (2001) Darwin s theory for the grazing incidence geometry. Surf Sci 490 394-408... 

A Perkin Elmer Optima 3000 Spectrometer was used to determine the cation content of solutions. Samples and multielement standards (0,1,10 and 100 mgL" ) were diluted with 5% nitric acid. All vials used were cleaned with 1 M sulphuric acid. Detection limits are 3, 5, 0.1, 5, and 70 igL for Fe, Al, Ca, Na, and K, respectively. 

Similar investigations have been done in the temperature range 700-800 C by Volkovich. Saturated solutions were prepared by placing pressed oxide tablets into the melt and holding them for 2-3 h. The analysis of solution samples was performed by eomplexometrie titration. 

Here, because of the relatively small rotation of solutions, sample thickness is given in decimeters, and concentration c in grams per lOOmL of solvent. The sodium D line (/ = 589.3 nm) is often used as incident radiation, and measurement is performed at 25 °C. These parameters are indicated by quoting indices in the form [a] s. The molar or molecular rotation [[Pg.429]

Spark, flame and plasma excitation are applicable to the direct excitation of solution samples. Osumi et al. (1970) used spark excitation to a rotating disc electrode to obtain rare earth detection limits of 2 to 40 ppm in complex-spectra rare earth elements. They used a controlled atmosphere and the rare earth solution contained 60% methanol. The introduction of solutions into spark discharges via porous graphite electrode (Fadeeva and Karpenko, 1972) or as aerosols (Karpenko et al., 1974) has also provided satisfactory analyses. 

Quantitative measurement of solutes samples is possible thanks to the Beer-Lambert linear relation Eq. [7.9], which links the absorbance and concentration as follows ... 

Quenching of Fluorescence. Relative quantum yields of fluorescence of solutions sampled as above with a solution of certain amounts of 1,3-pentadiene were measured and the Stern-Volmer plotts were drawn. 1,3-Pentadiene did not quenched fluorescence from 1. 

Chemical analysis of solution samples from several operating formate plants showed total Cu concentrations from 103 to 130 goiter HCOOH concentrations from 33 to 88 g/liter and... 

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