Chemistry Lab

Atomic absorption spectrometry

AAS can be used to measure more than 60 elements with instrumentation that is comparatively inexpensive and simple to operate. The method has sufficient sensitivity to measure many of these elements at the concentrations present in clinical specimens (Haswell, 1991). The spectrometer consists of a light source, atomizer, monochromator, detector and readout/display. The essential feature of a good light source for AAS is to provide a high intensity, monochromatic output, which is achieved with hollow cathode or electrodeless discharge lamps. The monochromator, detector and display are similar to those of other spectrometers. The atomizer is any device that will generate ground-state atoms as a vapour within the light path of the instrument. In the case of serum calcium, for example, the element is present bound to protein, complexed with phosphate and as free Ca2+. Atomization requires: (i) removal of solvent (drying), (ii) separation from anionic or other components of the
matrix to give Ca2+ and (iii) reduction (Ca2+ + 2e− →Ca0). The necessary energy is supplied as heat from either a flame, or an electrically heated furnace.

Atomic Absorption Spectroscopy (AAS):

Principle: The sample is vaporized by aspiration of solution into a flame or evaporation from electrically heated surface (temperature range: 1800 – 31000 K). At this condition where the individual atoms co-exist, a beam of light is passed through them. The atoms will absorb in the visible and ultraviolet region resulting in changes in electronic structure (excited state). So, the resultant light beam coming out of the sample will be missing the light in the corresponding wave length, which is a measure of the characteristics of the sample.

Atomic Absorption Instrumentation

There are five basic components of an atomic absorption instrument:
1. The light source that emits the spectrum of the element of interest
2. An "absorption cell" in which atoms of the sample are produced (flame, graphite furnace, MHS cell, FIAS cell, FIMS cell)
3. A monochromator for light dispersion
4. A detector, which measures the light intensity and amplifies the signal
5. A display that shows the reading after it has been processed by the instrument electronics
There are two basic types of atomic absorption instruments: single-beam and double beam.

The following tests can done in this centre by Atomic absorption spectrometer
1. Analysis of Soils: Extractable Cations
2. Analysis of Soils: Exchangeable Cations
3. Analysis of Soils and Sediments: Total Cations
4. Analysis of Plant Tissue: Dry Ashing
5. Analysis of Plant Tissue: Wet Digestion
6. Analysis of Feeds: Wet Digestion
7. Analysis of Feeds: Dry Ashing
8. Analysis of Inorganic Fertilizers
9. Analysis of Fertilizers Containing Organic Matter
10. Analysis of Fertilizers: Potassium
11. Analysis of Fertilizers: Boron
12. Analysis of Fertilizers: Phosphorus
13. - Analysis of Fertilizers: Molybdenum
14. Analysis of Serum and Plasma: Calcium and Magnesium
15. Analysis of Serum and Plasma: Sodium and Potassium
16. Analysis of Serum: Iron and Total Iron Binding Capacity (TIBC)
17. Analysis of Serum: Lithium
18. Analysis of Serum and Plasma: Copper and Zinc
19. Analysis of Serum: Gold
20. Analysis of Blood: Iron in Hemoglobin
21. Analysis of Blood: Determination of Lead Using an Extraction Procedure
22. Analysis of Urine: Calcium, Magnesium, Sodium, and Potassium
23. Analysis of Urine: Lithium and Zinc
24. Analysis of Urine: Determination of Lead Using an Extraction Procedure
25. Analysis of Cerebrospinal Fluid: Calcium and Magnesium
26. Analysis of Cerebrospinal Fluid: Copper and Zinc
27. Analysis of Tissue: Zinc: Dry Ashing (Oxidation Procedure)
28. Analysis of Tissue: Zinc: Wet Ashing (Oxidation Procedure)
29. Analysis of Fingernails: Calcium, Zinc, Magnesium, Copper, and Iron
30. Analysis of Hair: Copper, Iron, Magnesium, Zinc, Lead.
31. Analysis of Diet: Antimony, Cadmium, Chromium, Cobalt, Manganese, Zinc
32. Analysis of Seawater: Determination of Major Cations
33. Analysis of Seawater: Determination of Soluble Metals
34. Analysis of Seawater: Determination of Metals in Particulate Matter
35. Analysis of Natural Waters
36. Analysis of Metallic Air Pollutants
37. Analysis of Various Materials for Beryllium
38. Analysis of Fresh Water: Determination of Total Chromium
39. EN-8 - Analysis of Natural Waters: Determination of Metals
40. Using an Extraction Procedure
41. Analysis of Foodstuffs
42. Analysis of Foodstuffs: Cadmium and Lead
43. Analysis of Meat and Meat Products
44. Analysis of Fish and Seafood: Wet Digestion
45. Analysis of Fish and Seafood: Dry Ashing Procedure
46. Analysis of Baking Powder: Aluminum
47. Analysis of Whole Kernel Corn: Heavy Metals
48. Analysis of Edible Oils: Char-Ashing Technique
49. Analysis of Edible Fats and Oils: Direct Solvent Method
50. Analysis of Tea and Instant Tea: Copper, Nickel
51. Analysis of Fruit Juice
52. Analysis of Milk
53. Analysis of Evaporated Milk: Lead
54. Analysis of Wine
55. Analysis of Alcoholic Beverages: Copper, Iron
56. Analysis of Beer
57. Analysis of Food Coloring Dyes: Lead
58. Analysis of Pistol Bullets
59. Analysis of Paint Scrapings
60. Analysis of Heroin
61. Analysis of Ceramics: Determination of Lead and Cadmium Extracted from Glazed Surfaces
62. Analysis of Bauxite
63. Analysis of Rocks and Soils: Determination of Mercury with a Flameless Technique
64. Analysis of Sulfide Minerals
65. Analysis of Silicates and Carbonates: Lithium Metaborate Fusion Procedure
66. Analysis of Soils and Ores: HF Dissolution Procedure
67. Analysis of Ores, Feeds, Tailings, and Concentrates: Silver and Gold Assay
68. Analysis of Cement: HCl Extraction Procedure
69. Analysis of Cements: Lithium Metaborate Fusion
70. Analysis of Tungsten Carbide
71. Analysis of Coal Ash
72. Analysis of Yttrium Phosphors
73. Analysis of Fluorescent Phosphors
74. Analysis of Glass and Ceramic Frit
75. Analysis of Photographic Fixing Solutions
76. Analysis of Uranium Compounds
77. Analysis of Polysiloxanes
78. Analysis of Vinyl Additives and Paint Additives
79. Analysis of Leather: Determination of Chromium
80. Analysis of High Purity Silver Chloride
81. Analysis of Paint
82. Analysis of Aluminum Alloys
83. Analysis of Magnesium Alloys
84. Analysis of Tungsten
85. Analysis of Niobium and Tantalum
86. Analysis of Lead, Tin, and Lead-Tin Alloys
87. Analysis of Copper Alloys
88. Analysis of Zirconium and Hafnium
89. Analysis of Titanium Alloys
90. Analysis of Nickel and Nickel Alloys
91. Analysis of Iron and Steels
92. Analysis of Gold
93. Analysis of Plating Solutions
94. Analysis of Steels and Brasses
95. Analysis of Jewelry Alloys
96. Analysis of Lubricating Oils: Determination of Wear Metals
97. Analysis of Lubricating Oils: Particle Size-Independent
98. Determination of Wear Metals
99. Analysis of Lubricating Oils and Additives: Calcium, Barium, Zinc
100. Analysis of Gasoline: Lead
101. Analysis of Fuel Oils: Vanadium, Sodium, Lead
102. Analysis of Gas Oils
103. Analysis of Petroleum Additives: Lead and Antimony
104. Analysis of Pharmaceutical Preparations
105. Analysis of Commercial Hand Lotions
106. Analysis of Cosmetics: Determination of Lead
107. Determination of Cyanocobalamin (Vitamin B12
108. Analysis of Insulin: Determination of Zinc
109. Analysis of Pharmaceutical Preparations: Determination of Aluminum
110. Analysis of Polypropylene
111. Analysis of Textiles
112. Analysis of Synthetic Fibers
113. Analysis of Wool
114. Analysis of Cellulose
115. Analysis of Synthetic Fibers: Determination of Gold
116. General Procedure for the Indirect Determination of Sulfate
117. General Procedure for the Indirect Determination of Phosphate
118. General Procedure for the Indirect Determination of Chloride