Flame emission spectroscopy, water analysis

Water Analysis by Atomic Absorption and Flame Emission Spectroscopy... 

This study was conducted for the purpose of evaluating atomic absorption and flame emission spectroscopy for the routine quantitative analysis of large numbers of water samples for elements present in quantities ranging from large to trace amounts. 

Numerous methods for determining macro concentrations of molybdenum are available. Optical emission spectroscopy has been used in survey-type analyses (2), but it does not have adequate sensitivity to measure part-per-billion levels. X-ray fluorescence has been applied for part-per-million levels but cannot be readily extended to the lower levels of interest to the Project. Kinetic methods (3) and colorimetry with suitable pre-concentration (4) are capable of measuring part-per-billion levels of molybdenum but have not been applied to petroleum analysis. Molybdenum has been determined by atomic absorption techniques in such materials as sea water, biological tissue, and soils (5,6,7), Although a procedure for determining metals including molybdenum in petroleum by atomic absorption has been reported (8), no actual data are given for molybdenum. Flame and heated vaporization atomic absorption of aqueous solutions of ashed samples were selected by the Project for concurrent study in two separate laboratories. 

His laboratory is concerned with the analysis of a wide range of materials which include a variety of biological specimens, mineral samples, air particulate matter, and water samples. The information obtained is used to evaluate various individual and environmental problems. Two of the techniques which have been used for water analysis are atomic absorption (J, 4) and flame emission (2) spectroscopy, and a study of factors aflFecting these methods is described here. The samples came from a number of sources which included well water and city water. Consequently, the concentration ranges of some of the elements were quite wide. Five determinations were made daily on both the samples and standards for each element over a period of several months to provide suflBcient data for an adequate evaluation of precision. At present, ten elements (Na, K, Ca, Mg, Zn, Pb, Mn, Cu, Fe, and Ni) are being determined quantitatively. 

Even with the diflBculties cited above, the combination of flame emission and atomic absorption spectroscopy has become in a very short time one of our better methods for the analysis of waters for cations for the following reasons limited sample preparations necessary, high sensitivity, good analytical precision, low cost, and simphcity of equipment. 

Of the different techniques for atomic emission spectroscopy (AES) only those which use a flame or an ICP are of any interest for analysis of biomedical specimens. Flame AES, also called flame photometry, has been an essential technique within clinical laboratories for measuring the major cations, sodium and potassium. This technique, usually with an air-propane flame, was also used to determine lithium in specimens from patients who were given this element to treat depression, and was employed by virtually all clinical laboratories throughout the world until the recent development of reliable, rapid-response ion selective electrodes. Biological fluids need only to be diluted with water and in modern equipment the diluter is an integral part of the instrument so that a specimen of plasma or urine can be introduced without any preliminary treatment. 

Analytical methods of atomic spectroscopy have been used in forestry and wood product research since their earliest development. Nowadays, almost all of the spectroscopic techniques available are employed in the analysis of metals and trace elements in diverse samples of industrial and environmental origin. The techniques that find most regular application include flame atomic absorption spectroscopy (F-AAS), graphite furnace atomic absorption spectroscopy (GF-AAS), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and, occasionally, also direct current plasma atomic emission spectroscopy (DCP-AES). In many applications F-AAS is a sufficiently sensitive and precise technique however, in the analysis of some environmental samples for trace elements (forest soils, plant material and water) where concentrations may be very low (of the order of 100 ng mL" ) the greater sensitivity of GF-AAS and ICP/DCP-AES is required. In considering the applications of atomic spectroscopy to forestry and... 

See also Atomic Absorption Spectrometry Flame. Atomic Emission Spectrometry Flame Photometry. Carbohydrates Starch Dietary Fiber Measured as Nonstarch Polysaccharides in Plant Foods. Chiroptical Analysis. Essential Oils. Ethanol. Food and Nutritional Analysis Antioxidants and Preservatives Contaminants. Isotope Ratio Measurements. Liquid Chromatography Food Applications. Nuclear Magnetic Resonance Spectroscopy Appiications Food. Optical Spectroscopy Refractometry and Reflectometry. Pesticides. Sampiing Theory. Vitamins Fat-Soluble Water-Soluble. Water Determination. 

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