EPA 660/2-74-001 JANUARY 1974 Environmental Protection Technology Series Multielement Analysis of Environmental Samples By Spark Source Mass Spectrornetry National Environmental Research Center Office of Research and Development U.S. Environmental Protection Agency Corvallis, Oregon 97330 ------- RESEARCH REPORTING SERIES Research reports of the Oft'ice of Research and Monitoring, Environmental Protection Avjency, have been grouped into five series. These five bread categories were established to facilitate further development and application of environmental technology. Elimination of traditional grouping was consciously planned to foster technology transfer and a maximum interface in related fields. The five series are: 1. Environmental Health Effects Eesearch 2. Environmental Protection Technology 3. Ecological Research U. Environmental Monitoring 5. Socioeconomic Environmental Studies This report has been assigned to the ENVIRONMENTAL PROTECTION TECHNOLOGY series. This series describes research performed to develop and demonstrate instrumentation, equipment and methodology to repair or prevent environmental degradation from point and non-point sources of pollution. This work provides the new or improved technology required for the control and treatment of pollution sources to meet environmental quality standards. ------- EPA-660/2-74-001 January 1974 MULTIELEMENT ANALYSIS OF ENVIRONMENTAL SAMPLES BY SPARK SOURCE MASS SPECTROMETRY by Charles E. Taylor William J. Taylor Southeast Environmental Research Laboratory College Station Road Athens, Georgia 30601 Project 16ADN-22 Program Element #1BA027 National Environmental Research Center Office of Research and Development U. S. Environmental Protection Agency Corvallis, Oregon 97330 For sale by the Superintendent ol Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 65 cents ------- ABSTRACT A spark source mass spectrometer that uses electronic detection- and a dedicated data analysis system was applied to a survey type trace analysis for chemical elements. Errors in the data system software were identified and corrected. Modifications to the system permit identification and quantitation of 72 elements at the part per billion level in water samples. ii ------- CONTENTS Page Abstract ii List of Figures List of Tables Acknowledgements Sections I Conclusions 1 II Recommendations 2 III Introduction 3 IV Experimental 4 V Results and Discussion g VI References 23 iii ------- FIGURES Page 1 Accurate Mass Data 9 2 Original Interpretation of Data 10 3 Modified Interpretation of +1 and +2 12 Ion Data 4 Sample #1 Bar Graph 14 5 Sample #2 Bar Graph 15 ------- TABLES No. 1 Group I Coefficients of Variation 16 2 Group II Coefficients of Variation 17 3 SS Analysis of Effluent Sample 18 4 Relative Sensitivity Study in Sediment 19 Sample 5 SS Analysis of Reservoir Water 21 ------- ACKNOWLEDGMENTS The help of W. H. McDaniel, Environmental Protection Agency, Surveillance and Analysis Division, Chemical Services Bnfcnch, Region IV, in providing comparison analyses by atomic absorption is gratefully acknowledged Vi ------- SECTION I CONCLUSIONS Survey type analysis for trace elements in natural samples can be accomplished using spark source mass spectrometry (SSMS). Weight ratios of up to 100:1 in synthetic samples showed no detrimental effect on spark source data. Valid results have been obtained for multi- element analyses of sediments. The concentration of elements in sediments ranged from the percentage level to the part per million level. Using the modified software programs and existing SSMS equipment, 72 naturally occurring elements can be identified and quantitated at the part per billion (ppb) level in water samples. ------- SECTION II RECOMMENDATION Spark source mass spectrometry should be used for survey multielement analyses to clearly and rapidly identify problem elements in the environment. Because spark source is not so limited by interference, it should also be used as a back-up for more limited analytical techniques, such as atomic absorption and emission spectroscopy. ------- SECTION III INTRODUCTION Any elements or their compounds are pollutants if they occur at concentrations that adversely affect water usage. Because these concentrations may be very low, a method of trace analysis for a broad survey of chemical elements is essential to pollution monitoring. Emission and atomic absorption spectroscopy are each,currently used for such applications. However, using emission spectroscopy, one can routinely analyze for only 18-20 elements; atomic absorption is even more limited. The spark source mass spectrometer with its related data system combines sensitivity and broad range analysis capability with convenient analysis time. To assess the applicability of spark source mass spectrometry to the analysis of water and sediments we conducted this study evaluating a new computerized electronic detection system. ------- SECTION IV EXPERIMENTAL. The instrument used was an AEI MS 702 spark source mass spectrometer equipped with electronic detection. Acces- sories allow either peak switching or scanning for data collection. Peak switching is used when the analyst is interested in a more precise recording of a few peak intensities than is provided by a normal scan. It is used when major interest is in 2 or 3 elements. Switching is also used when isotopic dilution methods are required for ultimate accuracy in spark source (SS) analyses. Scanning is a survey analysis application and can include the total spectrum to encompass all known isotopes. The less precise measurements obtained from scanning are accept- able when the analyst requires a rapid survey, trace analysis system. The spark source mass spectrometer is equipped with an AEI data reduction system; this includes a SS interface, a Digital Equipment Corporation (DEC) PDP8/e 4K Computer, a 12-bit A/D Converter, a DF 32 and DS 32 disc memory, a teletype and high speed reader/punch and vendor- supplied DS-40 software. All data to be discussed were taken using the electronic detection and data system. The data system is functional only when the SS system operates in the scanning mode. The DS-40 software is not equipped for photographic plate or peak switching data. Calibration standards and other synthetic samples used to obtain relative sensitivites and to check out the 4 ------- system were made up from commercially available metals, powders, and solutions. Standard samples were mixed in solution and dried onto high purity graphite. The graphite- sample was mixed using a Spex mill and pressed into electrodes using an AEI die and polyethylene slugs. Although graphite was a very good matrix for electrode material, it presented some problems to the original software. The complex ions, C~, C, , ..., Con (composed 12 13 of both isotopes, C and C) caused false elemental identification and some erroneous quantitative data. Changes of analytical and confirmatory mass-to-charge ratios (m/e's) were required in the software. The necessary changes were made as single element tapes that replaced original software data on the disc memory system. Relative sensitivities were determined in a series of samples that contained yttrium and one or more of the 70 elements of interest in equal portions by weight. Using yttrium as the internal standard, the relative sensitivity data were combined with the weight conver- sion factor to yield the parameter K in the concentra- tion equation (Equation 1) . Equation 1 Concentration Calculation = Concentration where Ael = Area of analytical isotope of element in question Astd = Area of analytical isotope of standard ------- = Abundance factor of element in question (100/isotopic abundance of analytical isotope) Fstd = Abidance factor of standard (100/isotopic abundance of analytical isotope) Cgtd = Concentration of standard element. The units used to express the standard con- centration value define the units of "concentration," since the remainder of the equation is unitless. K = [weight conversion factor x relative sensitivity] Weight conversion factor = a.m.u. element/a. m.u. standard Using standards in various mixtures of elements and in various concentration ranges, we identified two major problems with the original data system software supplied by the vendor. Multiply-charged ions are very important in SS analysis using electronic detection since the low resolution inherent in this mode of operation does not allow reliable isotope ratio confirmation. False inter- pretations in some analyses were made by the data system when ions of +2 and/or +3 charges (+2 and/or +3 ions) were used as the analytical m/e or the confirming multiply- charged ion. This problem occurred at masses of £ 80 amu, where + 2 and +3 ions may occur. The original software used a +_ 0.2 amu tolerance to accept or reject a singal as the analytical or confirming mass of a given element. For example, for an iron analysis at 56 amu, the computer-calculated signal had only to fall between 55.8 amu and 56.2 amu to be accepted at the 56Fe. The tolerance window of + 0.2 amu was changed to + 0.09 amu, a figure based on tests involving a series of stand- ards. Samples of elements at a 100:1 weight ratio were used for this test. The complex spectra in the < 80 mass ------- range yielded no false analyses using the +0.09 amu tolerance. Changing the tolerance window brought to light another, less obvious, problem. Using the +0.09 tolerance, we found that isotopic weight values in one subroutine had been programmed using nominal instead of accurate mass values, e.g., 89 instead of 88.91 for Y. The programming was not consistent, since some subroutines of the soft- ware used accurate mass values. When the +0.09 amu tolerance was applied, the error had to be corrected. Further explanation of the interpretation details2'3'4 is in the literature and will not be fully explored here. Incorporation of all software changes were made, and the revised program was copied onto punched tape using a SERL Disc Dump/Restore tape and DEC-08-YXlA-PD-Binary Punch Teletype tape. The modified program now can be loaded into the data system in about 10 minutes compared to 45 minutes for the original software. The present program does not require manual changes of any values; the original program required 6 hours of manual entry of necessary changes. ------- SECTION V RESULTS AND DISCUSSION Equation 1 is used in the software for analytical cal- culations. The values in the original software were converted from ppm atomic to a weight basis by making K a product of the weight conversion factor and the relative sensitivity of the element in question. Figure 1 is an accurage mass listing of a complex syn- thetic sample. Peaks are numbered (Pk.No.) starting with the highest mass detected, designated "1", down to the lowest mass, assigned the highest peak number. The normalized intensity (Norm.Inty.) is the integrated peak area normalized to the peak with the greatest raw intensity in the recorded spectrum. The accurate masses (Ace.Mass.) are calculated for each peak using the operator-supplied reference peaks, indicated by the letter (R) to the right of the accurate mass data. This part of the program was the portion of the original soft- ware that used accurate masses and was incompatible with the nominal values in the data interpretation program discussed earlier. Figure 2 shows interpreted data as processed by the original software. The column heading "Mass" denotes the analytical m/e. "Element" is the corresponding element. "PPM atomic" is the concentration expressed "++3" in ppm on an atomic basis. "+++?» indicates the con- firmation or non-confirmation of am element determined by the presence or absence of the multiply-charged ions. "Confirm isotopes" indicates whether or not a specified ratio of a given set of isotopes has been found for the 8 ------- PK. NORM. ACC. HO. IHTT. MASS 1 11 £73.55 e 74 271.18 3 10 £61.22 4 34 260.25 5 43 245.94 6 156 E4U.6B 7 9 232.72 8 13 231.S2 9 225 230.38 10 19 219.14 11 9 217.93 IE 21B lit. 96 13 5 209.40 14 11 288.40 IS 15 £07.34 16 S 206.32 17 *1 2*5.33 IB 13 2B4.41 19 69 284. IS 20 £38 19B.0S 21 3B74 197.82 22 1163 196.09 23 2159 I94.9B £4 1382 193.99 25 77 192.94 £6 £53 191.97 R 27 12 191.02 £8 4 190.03 £9 9 189.78 30 35 166.92 31 IEB 186.88 32 4 184.78 33 9 163.89 34 81 182.68 35 30 181.89 36 428 180.69 37 531 179.95 R 38 £7 178.85 39 9 I77i86 4* 13 176.85 41 479 175.96 42 21 174.95 43 IB5S 173.92 44 14»3 172.94 45 1339 171.93 46 701 110.93 47 1129 169.94 R 48 4483 168.95 49 £548 167.97 S* ISM 166.95 St £191 165.93 58 482« 164.96 PK. HO EW. ACC. HO. IMTY. MASS S3 1985 163.96 54 8864 162.94 SS 94B 1*1.96 56 946 160. 9T 57 1454 159.93 58 4278 IS3.9S 59 MBS 157.93 R 60 737 156.91 61 1964 155.94 68 784 154.94 63 1688 153.91 64 1797 152.95 65 3119 151.93 66 1528 158.94 67 1125 149.98 R 6B 1139 148.94 69 1497 147.93 79 593 146.96 71 1022 145.91 78 7»» 144.9» 73 89* 143.93 74 736 142.9S 7S 8116 141.91 76 1873 148.92 11 7S 139.90 78 5639 138.91 * 79 9 137.91 B0 72 116.88 81 321 138.95 88 674 131.98 S3 46 129.92 84 43 127.9* 85 £0 125.88 86 9 184.84 87 11 123.86 88 84 111.88 89 £45 180.95 99 448 119.91 R 91 181 18.84 Figure 1 Accurate Mti. oat» PK. NOAH. ACC. NO. 1NTT. MASS 92 41 117.82 93 33 116.87 94 74 115.82 95 267 114. 87 96 ft 113.se 97 £24 112.36 98 u in. as 99 13 110.36 100 1252 109. aa 101 60 lee. 96 IBS 4227 107.91 R 103 ES99 1SS.9S 104 1957 104.90 105 3286 103.90 106 6B4E IDE. 99 107 E61C lfil.92 10B 179B 1 90.91 109 1182 99.91 110 1474 98.93 III 418 98.58 112 357 97.96 113 1B4 97.51! 114 £56 97.00 US 9»6 95.97 116 19 94.91 117 17 93.94 118 £8 92.94 119 21 91.93 129 6 S9.9S 181 3S12 88.91 R 122 173 >7.99 123 495 86.98 124 256 86.43 125 361 SS.99 126 £14 8S.49 127 79S 84.97 128 28B2 84.48 129 £127 84.00 139 425 83.48 131 884 82. 98 132 £018 82.48 133 $76 81.99 134 see 81.49 131 505 80.99 136 327 80.48 137 SSS 19.97 138 ESBS 79.48 139 490 78.98 14* £81 78.48 141 484 17.98 142 £92 77.48 143 629 76.97 PK. Nu.>i,. ACC. NO. IHTY. MASS 144 1696 76.48 145 777 75.97 146 1394 75.47 147 371 74.97 148 341 74.46 R 149 S3» 71.9* 158 374 73.47 151 794 72.97 1M> 195 72.45 153 1788 71.97 154 £89 71.45 155 699 70.95 156 8827 79.45 1ST 53 69.94 153 394B 69.4* 159 101 «.93 160 23 66.43 161 19 65.95 162 111 »*»» 163 46 65.29 164 1*S 64.96 165 84 64.62 166 33 63.9 1 167 17 6(.«« 168 £9 6I.9£ 169 432 68.94 II 17* 3918 59.93 171 12 58.39 17E 36 58.60 173 106 57. 9£ 174 43 57.60 175 *1 57.39 176 51 56.92 177 64 56.6* 178 361 56.27 179 866 55.91 180 92 55.61 It | 142 55. £7 1*8 4452 54.87 1*3 181 54.60 PK. NOS.-1. ACC. NO. INTY. MASS 184 62 54. £8 IBS 640 53.93 186 S3 53.61 187 65 53.28 IBB 1147 52.94 109 B3 52.62 198 JtsS SE.44 19 1 55 S£.£9 192 SSI 51.94 193 46 51.63 194 £978 51.44 195 1162 50. 95 R 196 57 50.63 197 332 S0.«0 198 303 49.96 199 £7 49.63 E00 E24 49.45 £81 61 49.30 202 SV1 48.98 £03 73 48.64 * 204 6 48.48 295 24 48.31 216 48*3 47. «9 £07 30 47.64 E0B 118 47.31 £89 574 46.98 21* 869 46.92 211 76 45.97 £12 6S73 44.97 213 4B3S 4«.47 214 S42 44.811 £15 19 43.46 £16 8 42.98 217 £9 42. CB 2U 16 42.85 219 35 41.99 220 16 41.24 ££1 112 48.9« 222 8392 39.97 2£3 19 39.74 £24 1718 38.97 R 2ES 67 36. « £26 7989 36.99 £27 ££ 16.65 22* 9327 36.01 829 95 35.E9 23* T89B 34.99 231 16 34.75 £3K «£ 34.65 £33 £99 34.32 £14 133 31.99 135 97 33.65 HO'. 1HTTV MASS 236 79 33.33 C37 54 32.99 E3B 246 32*** £39 793 31.0* £40 4*£ 30.01 «41 l»1£ S9.6T £42 423 £9.01 243 745E 88.91 f«4 6 C7.49 £45 3845 87.01 £46 C4I 26.02 £47 14 E5.76 148 84 £S.S* £49 3*9 £ £S.»S S3* 14 £4.S» 231 3M2 24V84 SS2 23 83- «» (S3 8685 83.** SS4 9316 £2.48 R JSS 44 81.99 SS6 18 M.99 . J5-J 4 £».49 £58 8769 2*.** 259 75 19.5* 86* S 19.11 261 1218 U.'S» 262 517 16.62 263 4578 17.5* 264 £55 17.08 £65 640E 16.81 £66 173 15.49 R 267 BS4 14.99 268 !» 14. Bl 269 ' 8*6 13. 56 £7* 71 11.67 £71 19 11.31 272 >73 11.13 £73 231 l*.*3 S74 46 9.33 (75 4579 9.08 X INTCRPRIT 7 IT ------- Figure 2 MASS CLEMENT 197 C-OLD 195 PLATINUM 193 1RID1UM 189 OSHIUtl 182* TUNGSTEN 181 TANTALUM 176 HAFNIl'W 175 LUTECIUM 1(9 THULIUM 166 ERBIUM 165 HOLM KIM 163 DYSPROSIUM 159 TERBIUM 158 GADOLINIUM S3 EUROPIUM 47 SAHAP11IM 46 NEODTMIUM 41 PRASEODYME 40 CERIUM 139 LANTHANUM 138 BARIUM 133 CESIUM 123 TELLURIUM 121 ANTIMONY IIS TIM H5 INDIUM 111 CADMIUM 105 PALLADIUM 183 RHODIUM let RUTHENIUM 93 NIOBIUM 90 Zl RCON1 UM 89 YTTRIUM 83 STRONTIUM 85 RUBIDIUM 79 BROMINE SB SELENIUM 75 ARSENIC 72 GERMANIUM 69 GALLIUM 66 ZINC MASS ELEMENT 63 COPPER 60 NICKEL 59 COBALT 9« I RON 55 MANGANESE 58 CHROMIUM 51 VANADIUM 48 TITANIUM 4S SCAND1IM 40 CALCIUM 3V POTASSIUM 34 SULPHUR 31 PHOSPHORUS 28 SILICON 27 ALIMINIUM 24 MAGNE SI UM 23 SODIUM 10 FLUORINE 16 OXYGEN 14 NITROGEN 1 1 BORON 9 BERYLLIUM PPM ATOM1 C 66 73 1 11.58 2. 12 3.81 1.96 7.37 .60 .37 77.CH 1 13.20 69.37 155.98 73.68 97.06 58*62 67.48 102*14 66.71 1.42 97.11 .24 5.54 2*40 7.60 2.99 3.56 1.85 151.71 117.64 182.76 .49 STANDARD 3.58 19.17 16.68 IS. 09 6.43 1 1 3. S6 2.96 1.21 PPM ATOMIC .46 .21 3.05 76.60 16.96 2«.0£ us. a* 104.60 41.20 32.40 55.00 13.66 141.18 55.69 67.22 144.56 .09 1 10*27 172.22 SB. IS 78.86 END OF f*T ***? 2* NO NO NO NO NO NO 2+ 2* 2* 2* 2+ 2* 2* 2+ 2* 2* NO 8+ NO 2* NO NO NO 2+ 2+ 2* 2+ 2+ a* NO 2+ NO NO NO 2+ 2* 2+ **7 *»»7 NO 2* 3* 2* NO 2* 2+ 2* NO 2* NO 2* NO 2* NO 8* a* NO NO MO NO RIM CONFIRM ISOTOPES YES NO NO NO - NO NO . NO - YES - YES YES NO YES - NO - NO - YES NO YES NO NO NO - YES - NO NO YES NO . NO NO YES COMF1 m ISOTOPES NO . NO _ NO - YES _ NO NO NO - NO . NO _ - - . YES - CHECK COMPLEX OVERLAP IONS 176 174 172 170 174 156 162 160 154 156 150 144 146 140 142 132 198 128 192 06 > 87) 86) 95) 87) 79) 81) 80) 77) 78) 75) 72> 73) 74) 71) 66) 661 64) 64) CHECK COMPLEX OVERLAP IONS 126< 189< 130( |95( !I6< I74( 1 1*J< 177C I6«< I08( I62C 104( 156( I0*< 159< 108( I53< UK B6( 82( 108< 66( 99t »6< 97< 60( 48( 52( 78 ( 3tt( ST< 34 ( SI 20 30 45 e* 30 63) 63> 65) 65) 5(1) 56) 59> 59) 56) 54 > 54) SC) 52) 53) 53) 51) 51) 4?) 43) Ml 34) 33) 33) 32) S9t 30) 24) 26) 26) 19 > 19) 17) 17) 14) 15) 15) 10) 10) 10 ------- element. This column should be of little interest be- cause of interference from other isotopes and complex ions. "Check overlap" reminds the operator of possible multiply-charged ion interferences. "Complex ions" is a printout of matrix atoms that could possibly interfere at a given m/e. These ions, in general, in a graphite matrix-water analysis are constant and this portion of the analysis is bypassed to save computer time. The1choice of a reliable analytical mass is exemplified in Figures 2 and 3. Titanium has isotopes of 46, 47, 48, 49, and 50 amu, all of which are listed in Figure 1. Since polycarbon ion interference exists at 48 and 49 amu, the choices are reduced to 46, 47, and 50 amu. Possible interfering isotopes are Ca and V, leaving 47 as a probable analytical mass. Possible interference exists at mass 47 from a multiply-charged ion of mass 94, which, in this case, is listed as present in Figure 1. These interferences leave only two logical choices 47 for the analytical mass. Since Ti is a more abundant 49 isotope than Ti t the other available odd number mass, 47 the multiply-charged Ti isotope at 23.5 amu is used for identification and quantitation. Errors present in the use of multiply-charged ions in the original program have been corrected. These errors occurred in analyses that had detectable 4-2 and/or +3 ions occurring within a nominal amu (Figure 1). This error was possible because of a wide tolerance (0.2 amu) in the original software. After the tolerance was changed to £ 0.09 amu, all masses used in data interpretation had to be changed in the software, since the original software used nominal masses for data interpretation. The differences between 11 ------- Figure 3 Modified Interpretation of +1 and +2 Ion Data JULY SEVENTEEN 197 195 191 189 182 175 172 85 167 165 163 159 158 153 147 143 141 140 139 138 66 188 118 its III IBS 51 50 95 89 43 28 25 24 83 20 20 18 16 14 12 19 16 GOLD PLATINUM I RI DI UN OSMIUM TUNGSTEN LUTECIUM YTTERBIUM THULIUM ERBIUM HOLMIUM DYSPROSIUM TERBI UM GADOLINIUM EUROPIUM SAMARIUM NEODYMIUM PRASEODYME CERIUM LANTHANUM BARIUM CESIUM TELLURI UM TIN INDIUM CADMIUM PALLADI UM RHODIUM RUTHENIUM MOLYBDENUM YTTRI UM RUBI DI UM MANGANESE VANADI UM TITANIUM SCANDIUM CALCIUM POTASSIUM CHLORINE PHOSPHORUS ALUMINIUM SODIUM FLUORINE OXYGEN CONCEN TRATIONS 88.75 258.88 2.88 8. IS 7.29 .52 146.22 87.23 136.39 102.67 230.85 126.73 222.27 104.18 116.74 152.42 96.06 8.04 67. "01 .31 .49 2.8 1 1.89 2.32 3.80 101.65 52.31 77.83 1.41 STANDARD .66 .01 .70 1.47 103.97 3.86 .21 220.39 .41 .58 .63 .03 19.84 ++7 +++7 2+ 2+ NO NO NO NO 2* 2+ 2+ 2+ 2+ 2+ 2* 2+ 2+ 2* 2+ NO 2+ NO 2+ NO NO NO NO 2+ 2* 2+ NO 2+ 2+ 2* 2+ 2+ NO 2+ 2+ 2+ 2+ 2* NO NO CONFIRM CHECK COMPLEX ISOTOPES OVERLAP IONS YES NO NO NO NO YES YES ~ YES - YES YES NO NO - NO NO - YES NO NO NO NO NO - - - - NO - NO YES - - - - - - I69< J03C 10IC 190C 85( I70( 55( 82( SIC 76< 47< 7 1 { 4SC 40( 60( 39 ( 82( 3S( 31( 27( 23( 38C 57C 34 C 5I( 85) 51) 50) 95) 43) 85) 28) 28) 25) 25) 24) 24) 23) 20) 20) 20) 41) 18) 16) 14) 12) 19) 19) 17) 17) JULY SEVENTEEN (4 NITROGEN 11 BORON 9 BERYLLI UM 27.55 ++T NO 1.18 NO .94 NO END OF RUN CONFIRM ISOTOPES NO CHECK OVERLAP COMPLEX IONS 28( 30< 4SC 20( 30< 14) 15) IS) 10) 10) 12 ------- nominal mass and accurate mass calculated by the computer were in some cases greater than the new tolerance. In other cases, they allowed for very little instrumental and hardware error. The value of these changes can be seen by comparing the accurate mass, the original interpretation, and the modified system (Figures 1, 2, and 3). In the original interpretation (Figure 2) niobium is incorrectly reported and confirmed using the +2 ion. Confirmation of +2 for niobium was supposedly made at 93/2 amu or 46.5 amu. In checking the accurate mass listing (Figure 1) the only ion occurring between 46 and 47 amu is 46.32 amu, which 139 is a +3 ion of La. This error is due to the + 0.2 amu as the 46.5 amu confirmation. It can be seen in the output of the corrected system (Figure 3) that niobium is neither reported nor confirmed. This error occurred also for gallium, zinc, cobalt, and iron in the original data (figure 2). Using the modified software system, a series of samples having highly varying concentration ratios and atomic weight differences has been analyzed. Results are shown in Figures 4 and 5. Coefficients of variation for each element are given in Tables 1 and 2. These values are based on 9 separate runs using a fresh set of electrodes for each analysis. The statistical data shown agree with those reported earlier by this laboratory.2 Results of the analyses of natural samples show compar- able precision to the data shown in Tables 1 and 2. Tables 3 and 4 represent the analysis of an effluent sample sent to our laboratory. The sample was prepared by centrifugation. The liquid was then decanted carefully to preserve the integrity of the pellet. Two one- 13 ------- FIGURE 4 SAMPLE #1 GROUP I 5.5 5.0 4.5 4.0 ^ ^ 3.5 3.0 Z.5 2.0 1.5 1.0 0.5 0 - _ + _ - 1 ! T .. 1 2 > 1 " 1 h ' 1 1 1 ' «J + mi | 2 + 2 1 l > 4 ( 111] + 2 4 2 KEY I + 2 + i *2 1 I. 1 1 1 high valuer Average :.<>.» Value? Actuc 1 Co^C ( ppb J -|- 2 ( 1 1 > ..T ' T -* -*- 1 Ce Cs Te Sn In Rb Se Ge Ti Co Al 6 Be SAMPLE *l GROUP IE 500 450 400 350 300 250 20O ISO 100 50 25 - - I -1-; - Au f + i t Y 2 i b 1 .. i m E i -J 'r H II ... o Dy 1 i i ~"~ b ( KE ! i 4 i 1 1 1 id EJ S Y 1 i m fi High Value:- Average Low Values Ac'uo' CoriC- (ppti) " +; 1 -I T " T ° ' I 9 JL. T -"- , , , i .L 1 Jd Pr La Pd Rh Ru S 14 ------- 500 450 40O 350 300 250 200 150 100 50 25 FIGURE 5 SAMPLE *2 GROUP I 4-2 -J+i- r-M~ KEY -p ^^ High Values Average Low Values Aciuol Cone, (ppb) Ce Cs Te Sn In Mo Rb Se Ge Ti Co Al B SAMPLE *2 GROUP H 4.0 3,5 3.0 2.5 ZO 1.5 1.0 0.5 0 - KEY : ] _ [ High Value* Average Low Values _ Mciua* tone- ippo; - - .... -. -* ( .-.-. > 4 L -1 ..... ' < - V2 - Ell . i ... 4 . < » » * «i » ^ . » j i i .j i ^ h .... < i < i __ .... . < ^ _ ».-*. i « 1 1 1 i I » i . 1 ~T" [yn * I I i i I » i i Au Pt Yb Tm Er Ho Dy Tb Gd Em Sm NO Pr La Pd Rh Ru Sc 15 ------- Table 1. GROUP I COEFFICIENTS OF VARIATION EXPRESSED IN PERCENT Element Ce Cs Te Sn In Rb Se Ge V Ti Ca K P Al B Be Sample #1. SxlO1 2X101 2X101 SxlO1 2X101 SxlO1 SxlO1 2X101 SxlO1 2X101 IxlO1 SxlO1 SxlO1 3X101 2X101 2X101 Sample #2 38 53 73 60 70 38 33 16 16 21 19 45 33 31 33 53 16 ------- Table 2. GROUP II COEFFICIENTS OF VARIATION EXPRESSED IN PERCENT Element Au Pt Yb Tm Er Ho Dy Tb Gd Eu Sm Nd Pr La Pd Rh Ru Sc Sample #1 17 27 54 38 59 43 22 45 41 25 31 58 32 16 36 32 50 32 Sample #2 4X101 SxlO1 4X101 2X101 4X101 4X101 1 3X101 SxlO1 SxlO1 T 4X10-1 lOxlO1 3X101 6X101 2X101 4X101 i 10x10 4X101 17 ------- Table 3. ANALYSES OF EFFLUENT SAMPLE Part I - SS Analysis of Water (Results Expressed in Parts Per Million by Weight) Element Mg P Ca K Fe Al Avg 20 15 10 9 7 7 #1 27 15 12 14 7 11 #2 14 15 8 6 6 5 Element Pb Cu Zn Mn Sr Co Avg 0.6 0.6 0.5 0.3 0.2 0.1 .#1 0.8 0.5 0.6 0.4 0.2 0.09 #.2 0.4 0.7 0.4 0.2 0.2 0.08 Part II - SS Analysis of Major Concentration Elements in Sediment Analysis (Results in Weight Percent) Element Fe Mg Ca Mn Avg 10 4 2 0.8 #1 10.1 6 2.9 1.0 #2 9.8 3 1.8 0.6 Element K Al P Avg 0.3 0.3 0.2 #1 0.22 0.27 0.24 .#2 0.40 0,35 0.12 Part III - SS Analysis for the Lower Concentration Elements in Sediment (Results Expressed in Parts Per Million by Weight) Element Sr Ba Ti Zn Zr Ce Y Co Er Nd Avg 45 40 14 11 8 6 5 5 3 3 #1 35 33 18 14 10 8 6 8 3 3 #2 55 47 11 8 6 5 4 3 3 Element Sc La Sm Cu V Pb Nb Rb As Be Cs Avg 3 2 2 2 2 1 1 1 1 1 0.5 #1 3.0 1.6 2.0 3.2 1.4 0.9 1.4 0.96 0.5 0.8 0.5 #2 3.4 3.1 2.7 1.1 2.5 1.4 0.4 0.60 1.5 1.5 0.47 18 ------- Table. 4. RELATIVE SENSITIVITY STUDY IN SEDIMENT USING INDIUM AND YTTRIUM CROSS CHECK (Established Relative Sensitivities Have Been Applied to All Results) Part I Sediment Plus Standards Calculated Weight Percent Major Element Fe Mn Ca K p Al Mg Yttrium Standard 10 0.8 2.3 0.3 0.2 0.3 4.0 Indium Standard 9 1.0 2.5 0.2 0.1 0.2 4.4 Part II Dilution of Above Sample with More Unspiked Sample Calculated Concentration in ppm by Weight Minor Element Ce Ti La Ba Nb Zr Sr Yttrium Standard 6 14 4 40 1 8 45 Indium Standard 10 11 2 58 1 10 38 Part IIISediment with Added Elements Weighed amounts of these elements were aflded to the sediment for analysis using yttrium as the internal standard and applying relative sensitivities Weight Percent Added Found Ba Zr Sr 6.8 4.7 3.8 7.2 4.2 3.4 19 ------- railliliter water samples were spiked with yttrium as the internal standard. These were dried on graphite and compacted into electrodes for analysis. The sediment samples were dried at 110°C for two hours, weighed and spiked dry Using yttrium and indium as the internal standards. The validity of using relative sensitivity coefficients, which were obtained from very dilute solutions, in analyzing sediments was tested by two experiments. In the first of these, the sediment samples mentioned above were spiked with both yttrium and indium and analyzed using first yttrium and then indium as the internal standard. Table 4 (Parts I and II) shows a negligible difference between the values, establishing the validity of a single reference standard. In the second experiment, relatively gross amounts of barium, strontium, and zirconium salts were added to the sediment; the sample was analyzed using the dilute- solution-derived sensitivity coefficients relative to yttrium. Results (Table 4, Part III) are in excellent agreement with the known concentrations. The relative sensitivities calculated from solutions with concentra- tions at the ppm levels, were therefore suitable for this analysis with concentrations in the percent range. Taken together, these two experiments indicate that, for these elements, there is no significant shift in relative sensitivity coefficients between very dilute solutions and complex sediments. Background data from a reservoir study (Table 5) show another application of SS analysis of natural samples. The reservoir has been the site of a number of recurring fish kills. The SS data will be compared later to data 20 ------- Table 5. SS ANALYSES OF RESERVOIR WATER Element Pb Ba Ce Te Sn Cu Ni Co Cr V Zn Ti Fe Mn P Sr SS 2 ppb 160 ppb 2 ppb 1 ppb 10 ppb 5 ppb 8 ppb 5 ppb 20 ppb 3 ppb 60 ppb 20 ppb 2 ppm 60 ppb 30 ppb 2 ppm AA <_ 50 ppb* 12 ppb <_ 50 ppb* < 50 ppb* 40 ppb 3.5 ppm *AA detection limit for method used 21 ------- to be taken at the time of future fish kills. Comparison results with atomic absorption (AA) were available for some elements and are noted. Coefficients of variation for these SS data range from 19 to 50% and average 33% on the analysis. 22 ------- SECTION VI REFERENCES McKee, J. E., and H. W. Wolf, Editors. Potential Pollutants. In: Water Quality Criteria, Second Edition. California State Water Resources Control Board. Pasadena, California. Publication 3-A. 1963. p. 123-299. Taylor, C. E., J. M. McGuire, and W. H. McDaniel. Spark Source Mass Spectra for Water Analysis. U. S. Environmental Protection Agency. (Presented at the 20th Annual Conference on Mass Spectrometry). Dallas, Texas. June 4-9, 1972. Bingham, R.f P. Powers, and W. Wolstenholme. Spark Source Mass Spectrometry using "Autospark" Sample Control and On-Line Data Processing. GEC-AEI (Electronics) Ltd., Scientific Apparatus Division. Publication T.P. 30. Brown, R., P. Powers, and W. Wolstenholme. Computerized Recording and Interpretation of Spark Source Mass Spectra. Analytical Chemistry. Vol. 43, £:1079-1085, July 1971. 23 ------- SELECTED WATER RESOURCES ABSTRACTS INPUT TRANSACTION FORM 1. Rep Accession Wo. w 4. Title MULTIELEMENT ANALYSIS OF ENVIRONMENTAL SAMPLES BY SPARK SOURCE MASS SPECTROMETRY Charles E. Taylor and William .J. Taylor Analytical Chemistry Branch Southeast Environmental Research Laboratory 5. 8. Pefforrainrr Report No. 10. Project No. 16ADN-22 11. ComractjGrsntNo. 13. Type (- Repor> und Period Coveted 12. Environmental Protection Agency IS. S Environmental Protection Agency report number EPA-660/2-74-001, January 1974 If!. Abstraci A spark source mass spectrometer that uses electronic detection and a dedicated data analysis system was applied to a survey type trace analysis for chemical elements. Errors in the data system software were identified and corrected. Modifications to the system permit identification and quantitation of 72 elements at the part per billion level in water samples. i7a. Descriptors *MaSS Spectrometry, *Trace Analysis, *Survey Analysis, *Analytical Techniques, *Water Pollution, *Sediment Analysis *spark Source Mass Spectrometry, Computerized Data System, Electrical Detection COWRR Field & Group Q 5A IS. Avail AbUity 19. S' "Utity C 'ass. (Report) 20. Securny Class. 21. i:-.\ of Pages 22, Price Send To: WATER RESOURCES SCIENTIFIC INFORMATION CENTER U.S. DEPARTMENT OF THE INTERIOR WASHINGTON, D. C. 2O24O f/.-K-fo- Charles E. Taylor [institution Southeast Environmental Res. Lab. ------- |