AA3001 Sample Preparation of Glass and Ceramic Materials for Atomic Absorption Analysis - Application Notes

[2] Fuse 0.2-1.0 grams of powderedglass with ~7x the amount of either sodiumhydroxide or potassium hydroxide for 10-30minutes at 400-500oC in an Ni or Pt crucible.The melt is cooled, dissolved in water, andpromptly analyzed for Si, B, Mo, Ti, V, Zn,halogens, P, and Al.[3] Moisten 0.1-0.5 grams of powderedglass with 1 ml of alcohol in a Pt or PtFedish, add ~5 ml water, 1 ml perchloric acid,1 ml sulfuric acid, and ~10 ml hydrofluoricacid. Digest on a steam bath or hot plate untilfumes are evolved. Add 1 ml sulfuric acid,10 ml hydrofluoric acid, and 2-10 ml methylalcohol. Take to near dryness (sulfuric acidminimizes undesirable reactions fromperchloric acid). Add 5-20 ml of hydrochloricacid, dilute, and analyze. This procedureallows the accurate determination of almostall elements except Si and B. Adding 0.1-0.2% lanthanum or strontium will improvethe response for Al, Ca, and Mg.The Buck 210VGP series can accuratelydetermine these major and minor elementsin ranges from 0.005% to over 20%,depending on the dilution used, with typicalprecision of 1.5% or better if using bracketedstandards. The entire procedure, frompreparation of sample to final analysis, canbe standardized to a simple format so that anovice lab technician can perform the testeasily.Analyst: Gerald J. DeMennaThe analysis of silicate-based glass andceramics has always been a moderatelydifficult job, since the components thatcomprise the glass are usually not stabletogether in solution. For example, mosttypical acidic digestions that solubilize siliconwill cause calcium fluoride to precipitate. Ifno fluoride is present, the silicon will not befully decomposed, and if the solution isheated, boron can be lost, etc.There are several industry standardprocedures that are used for specificelements, thereby requiring at least two (2)preparations to be used for the complete,reproducible analysis of each sample. If onlycertain components are important, thenperhaps a single preparation can beemployed. Listed below are some methodsdeveloped at Buck Scientific for use on theModel 210VGP Atomic AbsorptionSpectrophotometers.[1] Fuse 0.2-1.0 grams of powderedglass with 5x the amount of a mixed lithiumcarbonate/zinc oxide flux (2:1) for 10-15minutes at 900-950oC in an Ni or Pt crucible.Cool and dissolve the melt in hydrochloricacid (1:1) with warming. The resultantsolution is quantitatively diluted, filtered toremove insoluble silica, and analyzed for Ca,Mg, Al, B, Na, K, Fe, Cu, and Mn. If Cr, V,Ti or Mo are to be determined, the flux shouldcontain ~1/2 part sodium peroxide, or the“melt” can be dissolved in 25% hydrochloricacid and 10% hydrogen peroxide withsatisfactory results.Sample Preparation ofGlass and Ceramic Materialsfor Atomic Absorption AnalysisSIC: 321, 322, 3253, 326B U C KScientificApplication Note#AA3001A9/95Analytical Results for Standard Glass SamplesSamples: Standard Reference Materials from NIST/NBS, ASTM and BCSPreparation: Method #2 for Si, Al, Zn & B; #3 for the othersCalibration: Buck Certified Atomic Absorption StandardsInstrument: The Buck 210VGP Atomic Absorption SpectrophotometerConditions: Air/Acetylene flame, N2O/Acetylene flame, Integrate mode, Normal parameters[Potassium (K) and Sodium (Na) are done in emission mode]NOTE:All values listed below are in Weight Percent (%wt) in the original glass sample; [K]=known assay, [M]=measured data.Soda-Lime Borosilicate Lead “Crystal” (green) (hard, Hi-B) (tinted)Element [K] [M] [K] [M] [K] [M][#2 prep]Si 34.2 34.0 37.8 37.2 30.6 30.9Al 0.17 0.15 1.21 1.24 0.09 0.09 *Zn 0.18 0.19 .011 .009 1.11 1.09 #B 1.42 1.38 3.93 3.90 0.05 0.04[#3 prep]Na 10.0 10.3 2.97 3.08 4.22 4.25K 0.49 0.48 .012 .011 6.97 7.03Zn 0.16 0.18 .006 .007 1.07 1.04 #Ca 6.15 5.97 .007 .009 0.28 0.30Mg 2.35 2.40 .008 .008 0.05 0.04Mn .015 .016 .004 .005 0.11 0.12Ba 0.17 0.15 4.77 4.61 1.38 1.42Al 0.15 0.14 1.22 1.20 0.08 0.07 *Pb <0.01 <0.01 <0.01 <0.01 16.3 16.1Cu 0.08 0.09 .002 .002 0.16 0.15Fe 4.08 3.95 .024 .022 0.41 0.42The above data shows the powerful flexibility and stability of the Buck 210VGP system for the wide-ranging requirements ofthe glass and ceramics industry. The excellent correlation between the known and measured values ranges from 0.6% to 3.0%(average RSD = 1.6%) demonstrates the precision of the instrument. The fact that two different preparations gave superbreproducibility on two difficult elements, Zn (#) and Al (*), reveals the high accuracy of the chemistry.Basic System: $12,950.00Turnkey System: $18,160.00For detailed configuration, refer to Quote #AA4001AIncludes: All recommended lamps, standards, and accessories fornormal operation.1-800-562-556658 Fort Point Street l East Norwalk, CT 06855Phone: 203-853-9444 l Fax: 203-853-0569quality@bucksci.com l www.bucksci.comB U C KScientific[2] Fuse 0.2-1.0 grams of powderedglass with ~7x the amount of either sodiumhydroxide or potassium hydroxide for 10-30minutes at 400-500oC in an Ni or Pt crucible.The melt is cooled, dissolved in water, andpromptly analyzed for Si, B, Mo, Ti, V, Zn,halogens, P, and Al.[3] Moisten 0.1-0.5 grams of powderedglass with 1 ml of alcohol in a Pt or PtFedish, add ~5 ml water, 1 ml perchloric acid,1 ml sulfuric acid, and ~10 ml hydrofluoricacid. Digest on a steam bath or hot plate untilfumes are evolved. Add 1 ml sulfuric acid,10 ml hydrofluoric acid, and 2-10 ml methylalcohol. Take to near dryness (sulfuric acidminimizes undesirable reactions fromperchloric acid). Add 5-20 ml of hydrochloricacid, dilute, and analyze. This procedureallows the accurate determination of almostall elements except Si and B. Adding 0.1-0.2% lanthanum or strontium will improvethe response for Al, Ca, and Mg.The Buck 200A series can accuratelydetermine these major and minor elementsin ranges from 0.005% to over 20%,depending on the dilution used, with typicalprecision of 1.5% or better if using bracketedstandards. The entire procedure, frompreparation of sample to final analysis, canbe standardized to a simple format so that anovice lab technician can perform the testeasily.Analyst: Gerald J. DeMennaThe analysis of silicate-based glass andceramics has always been a moderatelydifficult job, since the components thatcomprise the glass are usually not stabletogether in solution. For example, mosttypical acidic digestions that solubilize siliconwill cause calcium fluoride to precipitate. Ifno fluoride is present, the silicon will not befully decomposed, and if the solution isheated, boron can be lost, etc.There are several industry standardprocedures that are used for specificelements, thereby requiring at least two (2)preparations to be used for the complete,reproducible analysis of each sample. If onlycertain components are important, thenperhaps a single preparation can beemployed. Listed below are some methodsdeveloped at Buck Scientific for use on theModel 200A Atomic Absorption Spectro-photometers.[1] Fuse 0.2-1.0 grams of powderedglass with 5x the amount of a mixed lithiumcarbonate/zinc oxide flux (2:1) for 10-15minutes at 900-950oC in an Ni or Pt crucible.Cool and dissolve the melt in hydrochloricacid (1:1) with warming. The resultantsolution is quantitatively diluted, filtered toremove insoluble silica, and analyzed for Ca,Mg, Al, B, Na, K, Fe, Cu, and Mn. If Cr, V,Ti or Mo are to be determined, the flux shouldcontain ~1/2 part sodium peroxide, or the“melt” can be dissolved in 25% hydrochloricacid and 10% hydrogen peroxide withsatisfactory results.Sample Preparation ofGlass and Ceramic Materialsfor Atomic Absorption AnalysisSIC: 321, 322, 3253, 326B U C KScientificApplication Note#AA3001B9/95Analytical Results for Standard Glass SamplesSamples: Standard Reference Materials from NIST/NBS, ASTM and BCSPreparation: Method #2 for Si, Al, Zn & B; #3 for the othersCalibration: Buck Certified Atomic Absorption StandardsInstrument: The Buck 200A Atomic Absorption SpectrophotometerConditions: Air/Acetylene flame, N2O/Acetylene flame, Integrate mode, Normal parameters[Potassium (K) and Sodium (Na) are done in emission mode]NOTE:All values listed below are in Weight Percent (%wt) in the original glass sample; [K]=known assay, [M]=measured data.Soda-Lime Borosilicate Lead “Crystal” (green) (hard, Hi-B) (tinted)Element [K] [M] [K] [M] [K] [M][#2 prep]Si 34.2 34.0 37.8 37.2 30.6 30.9Al 0.17 0.15 1.21 1.24 0.09 0.09 *Zn 0.18 0.19 .011 .009 1.11 1.09 #B 1.42 1.38 3.93 3.90 0.05 0.04[#3 prep]Na 10.0 10.3 2.97 3.08 4.22 4.25K 0.49 0.48 .012 .011 6.97 7.03Zn 0.16 0.18 .006 .007 1.07 1.04 #Ca 6.15 5.97 .007 .009 0.28 0.30Mg 2.35 2.40 .008 .008 0.05 0.04Mn .015 .016 .004 .005 0.11 0.12Ba 0.17 0.15 4.77 4.61 1.38 1.42Al 0.15 0.14 1.22 1.20 0.08 0.07 *Pb <0.01 <0.01 <0.01 <0.01 16.3 16.1Cu 0.08 0.09 .002 .002 0.16 0.15Fe 4.08 3.95 .024 .022 0.41 0.42The above data shows the powerful flexibility and stability of the Buck 200A system for the wide-ranging requirements of theglass and ceramics industry. The excellent correlation between the known and measured values ranges from 0.6% to 3.0%(average RSD = 1.6%) demonstrates the precision of the instrument. The fact that two different preparations gave superbreproducibility on two difficult elements, Zn (#) and Al (*), reveals the high accuracy of the chemistry.Basic System: $8,495.00Turnkey System: $13,705.00For detailed configuration, refer to Quote #AA4001BIncludes: All recommended lamps, standards, and accessories fornormal operation.1-800-562-556658 Fort Point Street l East Norwalk, CT 06855Phone: 203-853-9444 l Fax: 203-853-0569quality@bucksci.com l www.bucksci.comB U C KScientific