Atomic spectrophotometry

In modern times, most analyses are performed on an analytical instrument for, e.g., gas chromatography (GC), high-performance liquid chromatography (HPLC), ultra-violet/visible (UV) or infrared (IR) spectrophotometry, atomic absorption spectrometry, inductively coupled plasma mass spectrometry (ICP-MS), mass spectrometry. Each of these instruments has a limitation on the amount of an analyte that they can detect. This limitation can be expressed as the IDL, which may be defined as the smallest amount of an analyte that can be reliably detected or differentiated from the background on an instrument. 

The most important features of liquid membranes are that they olfer highly selective extraction, efficient enrichment of analytes from the matrix in only one step, and the possibility of automated interfacing to different analytical instruments such as liquid chromatography, gas chromatography, capillary zone electrophoresis, UV spectrophotometry, atomic absorption spectrometry, and mass spectrometry [82]. 

Dissolution of the sample is the method required in a number of spectroscopic and chromatographic techniques (e.g., UV-Vis spectrophotometry, atomic absorption spectroscopy (AAS), high performance liquid chromatography (HPLC), and thin-layer chromatography (TLC)). Selection of the suitable solvent is essential... 

At the heart of the ion chromatography system is an analytical column containing an ion exchange resin on which various anions (and/or cations) are separated before being detected and quantified by various detection techniques, such as spectrophotometry, atomic absorption spectrometry (metals) or conductivity (anions). 

A. L. Green, and J. P. Sauve, The Analysis of Gunshot Residue by Atomic Absorption Spectrophotometry, Atomic Absorption Newsletter 11 (Septem-ber-October 1972) 93. 

M3. Manning, D. C., and Slavin, W., Lithium isotope analysis by atomic absorption spectrophotometry. Atomic Absorption Newsletter No. 8. Perkin-Elmer Corp., Norwalk, Conn. (November 1962). 

The methods officially used in the wine trade transactions are summarized in Table 8.1. Generally, the OIV methods are officially adopted in the European Union without significant technical changes. The methods reported are mainly colorimetric, titrimetric, or use Atomic Emission Spectroscopy (AES, e.g. Flame Spectrophotometry), Atomic Absorption Spectroscopy (AAS), Hydride Generation-AAS (HG-AAS), Electrothermal-AAS (ET-AAS) and Vapour Atomic Flourescence Spectrophotometry (VAF). 

Chemical analysis provides much more precise data about the sample, particularly the determination of metallic elements, mainly lead, cadmium, iron, calcium, sodium as well a.s anions, chlorides, fluorides, nitrates, carbonates and sulphates. The analyses are performed most frequently by spectrophotometry, atomic absorption spectrometry, or polarography in recent years radionuclide X-ray fluorescence and activation analysis have been used. 

Holak, W. and Specchio, J.J. (199 i)rDetermination of total arsenic, As(lll) and As(V) in foods by atomic absorption spectrophotometry. Atomic Spectroscopy 12,105-108. 

Bunker, V.W., Hinks, L.J., Lawson, M.S. and Clayton, B.E. (1984). Assessment of zinc and copper status of healthy elderly people using metabolic balance studies and measurement of leucocyte concentrations, Amer. J. Clin. Nutr., 4Q, 1096-1102 Burguera, M., Burguera, J.L, Cergio Rivas, P., and Alarcon, O.M. (1986). Determination of copper, zinc, and iron in parotid saliva by flow injection with flame absorption spectrophotometry. Atomic Spectrosc., Z. 79-81... 

Minoia, C., Sabbioni, E., Apostoli, P., Pietra, R.. Pozzoli, L, Gallorini, M., Nicolaou, G.. Alessio, L., and Capodaglio, E. (1990). Trace element reference values in tissues from inhabitants of the european community I. A study of 46 elements in urine, blood and serum of Italian subjects, Sci. Total Environ., 25.89-105 Olsen. A.D., and Hamlin, W.B. (1968). Serum copper and zinc by atomic absorption spectrophotometry. Atom. Absorpt. Newsl., Z, 69-71 Plantz, M.R., Fritz, J.S., Smith, F.G., and Houk, R.S. (1989). Separation of trace metal complexes for samples of high salt content by inductively coupled plasma mass spectrometry, Anal. Chem., 1,149-153... 

Rocks. B.R., Shenwood, R.A., Bayford, L.M., and Riley, C. (1982). Zinc and copper determination in microsamples of serum by flow injection and atomic absorption spectroscopy. Ann. Clin. Biochem.. 12.338-344 Samela, S., and Vuori, E. (1984). Improved direct determination of copper and zinc in a single serum dilution by atomic absorption spectrophotometry. Atomic Spectrosc., 5, 146-149... 

Many analytical methods have been useful at the trace level flame photometry, spectrophotometry, atomic absorption and fluorescence spectroscopy,... 

Uric acid was determined by the method of Archibald (2). Calcium was determined using atomic absorption spectrophotometry (atomic absorption spectrophotometer Perkin Elmer 107). 

Quigley, M. N. Determination of Calcium in Analgesic Tablets Using Atomic Absorption Spectrophotometry, ... 

Koscielniak and Parczewski investigated the influence of A1 on the determination of Ca by atomic absorption spectrophotometry using the 2 factorial design shown in the following table. ... 

Provide an SOP for the determination of cadmium in lake sediments by atomic absorption spectrophotometry using a normal calibration curve. 

Determination of gold concentrations to ca 1 ppm in solution via atomic absorption spectrophotometry (62) has become an increasingly popular technique because it is available in most modem analytical laboratories and because it obviates extensive sample preparation. A more sensitive method for gold analysis is neutron activation, which permits accurate determination to levels < 1 ppb (63). The sensitivity arises from the high neutron-capture cross section (9.9 x 10 = 99 barns) of the only natural isotope, Au. The resulting isotope, Au, decays by P and y emission with a half-life of 2.7 d. 

Mineral and Chemical Composition. X-ray diffraction is used to determine the mineral composition of an Mg(OH)2 sample. Induced coupled plasma (icp) spectrophotometry is used to measure the atomic concentrations present in a sample. X-ray fluorescence analysis is another comparative instmmental method of determining chemical composition. 

Concurrent with requirements for low levels of mercurials in discharge water is the problem of their deterrnination. The older methods of wet chemistry are inadequate, and total rehance is placed on instmmental methods. The most popular is atomic absorption spectrophotometry, which rehes on the absorption of light by mercury vapor (4). Solutions of mercury compounds not stabilized with an excess of acid tend to hydrolyze to form yeUow-to-orange basic hydrates. These frequendy absorb onto the walls of containers and may interfere with analytical results when low levels (ppm) of mercury are determined. 

Analytical deterrnination of nickel in solution is usually made by atomic absorption spectrophotometry and, often, by x-ray fluorescence spectroscopy. 

Potassium is analyzed in chemicals that are used in the fertilizer industry and in finished fertilizers by flame photometric methods (44) or volumetric sodium tertraphenylboron methods (45) as approved by the AO AC. Gravimetric deterrnination of potassium as K2PtClg, known as the Lindo-Gladding method (46), and the wet-digestion deterrnination of potassium (47) have been declared surplus methods by the AO AC. Other methods used for control purposes and special analyses include atomic absorption spectrophotometry, inductively coupled plasma (icp) emission spectrophotometry, and a radiometric method based on measuring the radioactivity of the minute amount of the isotope present in all potassium compounds (48). 

Numerous methods have been pubUshed for the determination of trace amounts of tellurium (33—42). Instmmental analytical methods (qv) used to determine trace amounts of tellurium include atomic absorption spectrometry, flame, graphite furnace, and hydride generation inductively coupled argon plasma optical emission spectrometry inductively coupled plasma mass spectrometry neutron activation analysis and spectrophotometry (see Mass spectrometry Spectroscopy, optical). Other instmmental methods include polarography, potentiometry, emission spectroscopy, x-ray diffraction, and x-ray fluorescence. 

Spectrophotometric deterrnination at 550 nm is relatively insensitive and is useful for the deterrnination of vitamin B 2 in high potency products such as premixes. Thin-layer chromatography and open-column chromatography have been appHed to both the direct assay of cobalamins and to the fractionation and removal of interfering substances from sample extracts prior to microbiological or radioassay. Atomic absorption spectrophotometry of cobalt has been proposed for the deterrnination of vitamin B 2 in dry feeds. Chemical methods based on the estimation of cyanide or the presence of 5,6-dimethylben2irnida2ole in the vitamin B 2 molecule have not been widely used. 

Alkaline-earth metals are often deterruined volumetricaHy by complexometric titration at pH 10, using Eriochrome Black T as indicator. The most suitable complexing titrant for barium ion is a solution of diethylenetriaminepentaacetic acid (DTPA). Other alkaline earths, if present, are simultaneously titrated, and in the favored analytical procedure calcium and strontium are deterruined separately by atomic absorption spectrophotometry, and their values subtracted from the total to obtain the barium value. 

BeryUium aUoys ate usuaUy analyzed by optical emission or atomic absorption spectrophotometry. Low voltage spark emission spectrometry is used for the analysis of most copper-beryUium aUoys. Spectral interferences, other inter-element effects, metaUurgical effects, and sample inhomogeneity can degrade accuracy and precision and must be considered when constmcting a method (17). 

Metal Extraction. As with other carboxyhc acids, neodecanoic acid can be used in the solvent extraction of metal ions from aqueous solutions. Recent appHcations include the extraction of zinc from river water for deterrnination by atomic absorption spectrophotometry (105), the coextraction of metals such as nickel, cobalt, and copper with iron (106), and the recovery of copper from ammoniacal leaching solutions (107). 

Mean values from duplicate analyses of each of three samples by atomic absorption spectrophotometry. 

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