Analytical Methods for Atomic Absorption Spectroscopy

1 , 9/10/96 1:41 PMAnalytical Methods forAtomic , 9/10/96 1:41 PMNoticeThe information contained in this document is subject to change without MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THISMATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OFMERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Perkin-Elmershall not be liable for errors contained herein or for incidental consequential damages inconnection with the furnishing, performance, or use of this InformationReproduction or publication of this document in any form or format is prohibited withoutwritten permission of The Perkin-Elmer Corporation or any of its 1996 The Perkin-Elmer rights in the United States of InformationManualPart Date0303-0152 ABCDM arch 1964 November 1981 August 1994 September 1996 TrademarksPerkin-Elmer is a registered trademark of The Perkin-Elmer names, trademarks, etc.

2 Used in this document, even when not specificallymarked as such, are protected by , 9/10/96 1:41 PMSafety InformationThe Analytical Methods section describes methodologies using a widevariety of potentially hazardous chemicals (acids, bases, organicsolvents, etc.) Acid digestions, either at atmospheric pressure or atincreased pressure, may require special using any chemicals, acids, etc., you should be thoroughlyfamiliar with all hazards and safe handling practices. Observe themanufacturer's recommendations for use, storage, and disposal. Theserecommendations are normally provided in a safety data sheet suppliedwith the about laboratory safety and the handling of potentiallyhazardous chemicals can be found in the following: Furr, K.

3 , ed., CRC Handbook of Laboratory Safety, 3rd ed., TheChemical Rubber Co. Press, Florida, USA, 1990. Bretherick, L., Hazards in the Chemical Laboratory, 3rd ed., RoyalSociety of Chemistry, London, UK, , 9/10/96 1:41 PMContentsGeneral vs. Sources for Atomic Concentration vs. Detection Conditions Operating Sampling and standard conditions for the determination of individual elementsare listed alphabetically by elemental symbol in this - Analysis of Soils: Extractable - Analysis of Soils: Exchangeable - Analysis of Soils and Sediments: Total - Analysis of Plant Tissue: Dry - Analysis of Plant Tissue: Wet , 9/10/96 1:41 PMAY-6 - Analysis of Feeds: Wet - Analysis of Feeds: Dry - Analysis of Inorganic - Analysis of Fertilizers Containing Organic - Analysis of Fertilizers: - Analysis of Fertilizers: - Analysis of Fertilizers: - Analysis of Fertilizers: - Analysis of Serum and Plasma: Calcium and - Analysis of Serum and Plasma.

4 Sodium and - Analysis of Serum: Iron and Total Iron Binding Capacity(TIBC)..157BC-4 - Analysis of Serum: - Analysis of Serum and Plasma: Copper and - Analysis of Serum: - Analysis of Blood: Iron in - Analysis of Blood: Determination of Lead Using anExtraction - Analysis of Urine: Calcium, Magnesium, Sodium, - Analysis of Urine: Lithium and - Analysis of Urine: Determination of Lead Using anExtraction - Analysis of Cerebrospinal Fluid: Calcium - Analysis of Cerebrospinal Fluid: Copper and - Analysis of Tissue: Zinc: Dry Ashing (OxidationProcedure)..173BC-15 - Analysis of Tissue: Zinc: Wet Ashing (OxidationProcedure)..174BC-16 - Analysis of Fingernails: Calcium, Zinc, Magnesium,Copper, and - Analysis of Hair: Copper, Iron, Magnesium, Zinc, - Analysis of Diet: Antimony, Cadmium, Chromium,Cobalt, Manganese, - Analysis of Seawater: Determination of Major - Analysis of Seawater: Determination of Soluble , 9/10/96 1:41 PMEN-3 - Analysis of Seawater: Determination of Metals inParticulate - Analysis of Natural - Analysis of Metallic Air - Analysis of Various Materials for - Analysis of Fresh Water: Determination of - Analysis of Natural Waters: Determination of MetalsUsing an Extraction - Analysis of - Analysis of Foodstuffs: Cadmium and - Analysis of Meat and Meat - Analysis of Fish and Seafood.

5 Wet - Analysis of Fish and Seafood: Dry Ashing - Analysis of Baking Powder: - Analysis of Whole Kernel Corn: Heavy - Analysis of Edible Oils: Char-Ashing - Analysis of Edible Fats and Oils: Direct Solvent - Analysis of Tea and Instant Tea: Copper, - Analysis of Fruit - Analysis of - Analysis of Evaporated Milk: - Analysis of - Analysis of Alcoholic Beverages: Copper, - Analysis of - Analysis of Food Coloring Dyes: - Analysis of Pistol - Analysis of Paint - Analysis of - Analysis of Ceramics: Determination of Lead andCadmium Extracted from Glazed - Analysis of - Analysis of Rocks and Soils: Determination of Mercurywith a Flameless - Analysis of Sulfide , 9/10/96 1:41 PMGC-4R - Analysis of Silicates and Carbonates: LithiumMetaborate Fusion - Analysis of Soils and Ores: HF Dissolution - Analysis of Ores, Feeds, Tailings, and Concentrates:Silver and Gold - Analysis of Cement: HCl Extraction - Analysis of Cements: Lithium Metaborate - Analysis of Tungsten - Analysis of Coal - Analysis of Yttrium - Analysis of Fluorescent - Analysis of Glass and Ceramic - Analysis of Photographic Fixing - Analysis of Uranium - Analysis of - Analysis of Vinyl Additives and Paint - Analysis of Leather.

6 Determination of - Analysis of High Purity Silver - Analysis of - Analysis of Aluminum - Analysis of Magnesium - Analysis of - Analysis of Niobium and - Analysis of Lead, Tin, and Lead-Tin - Analysis of Copper - Analysis of Zirconium and - Analysis of Titanium - Analysis of Nickel and Nickel - Analysis of Iron and - Analysis of - Analysis of Plating - Analysis of Steels and - Analysis of Jewelry - Analysis of Lubricating Oils: Determination ofWear , 9/10/96 1:41 PMPC-2 - Analysis of Lubricating Oils: Particle Size-IndependentDetermination of Wear - Analysis of Lubricating Oils and Additives: Calcium,Barium, - Analysis of Gasoline: - Analysis of Fuel Oils: Vanadium, Sodium, - Analysis of Gas - Analysis of Petroleum Additives: Lead and - Analysis of Pharmaceutical - Analysis of Commercial Hand - Analysis of Cosmetics: Determination of - Determination of Cyanocobalamin (Vitamin B12).

7 284PH-5 - Analysis of Insulin: Determination of - Analysis of Pharmaceutical Preparations: Determinationof - Analysis of - Analysis of - Analysis of Synthetic - Analysis of - Analysis of - Analysis of Synthetic Fibers: Determination of - General Procedure for the Indirect Determination - General Procedure for the Indirect Determination - General Procedure for the Indirect Determination , 9/10/96 1:41 , 9/10/96 1:44 PMGeneral InformationEmission vs. Emission vs. Atomic Absorption Sources for Atomic Cathode Discharge Lamps (EDLs)..9 Burner Burner Flow Organic the Number of Concentration vs. Detection Concentration Check vs. , 9/10/96 1:44 Conditions Flame Emission to Use the Standard Conditions Standard Operating of Added of of the "Blank".

8 38 Cleanliness of Premix Burner Sampling and THGA Graphite Furnace Injection Injection Mercury and vs. , 9/10/96 1:44 PMEmission vs. AbsorptionAll modern Perkin-Elmer Atomic Absorption instruments are capable ofmeasuring both Atomic Absorption and Atomic emission. It is importantfor the operator to understand the processes that occur in element has a specific number of electrons associated with itsnucleus. The normal and most stable orbital configuration of an atom isknown as the "ground state." If energy is applied to an atom, the energywill be absorbed and an outer electron will be promoted to a less stableconfiguration known as the "excited state." Since this state is unstable,the atom will immediately return to the "ground state," releasing Atomic emission, the processes of excitation and decay shown inFigure 1 are both 1.

9 Excitation and DecayThe sample is subjected to a high-energy thermal environment in orderto produce excited-state atoms. This environment can be provided by aflame or, more recently, a plasma. However, since the excited state isunstable, the atoms spontaneously return to the "ground state" and emitlight. The emission spectrum of an element consists of a collection ofemission wavelengths called emission lines because of the discreteAtomic Emission4 Emission vs. , 9/10/96 1:44 PMnature of the emitted wavelengths. The intensity at an emission linewill increase as the number of excited atoms of the element process of Atomic Absorption is illustrated in Figure 2. Atomic Absorption ProcessThe "ground state" atom absorbs light energy of a specific wavelengthas it enters the "excited state.

10 " As the number of atoms in the light pathincreases, the amount of light absorbed also increases. By measuringthe amount of light absorbed, a quantitative determination of theamount of analyte can be made. The use of special light sources andcareful selection of wavelengths allow the specific determination ofindividual are some basic differences between Atomic emission and atomicabsorption. Using Atomic emission, the flame serves a dual purpose: itconverts the sample aerosol into an Atomic vapor and then thermallyelevates the atoms to an excited state. When these atoms return to theground state, they emit light which is detected by the instrument. Theintensity of light emitted is related to the concentration of the elementof interest in Atomic Absorption , the only function of the flame is to convert thesample aerosol into Atomic vapor which can then absorb light from theprimary light source (hollow cathode lamp or electrodeless dischargelamp).