Table VII. Recoveries of Organic and Inorganic Mercury, pg/l. Sample type
Raw sewage
Inorganic Hg f o u n d before spiking
Total Hg f o u n d before spiking
Inorganic Hg added
0.13
2.00 2.68
0.19 0.19 1.20
Artificial sample
0.00 0.00 0.00
Inorganic Hg found after spiking
2.50 5.00
1.00 0.88 1.00 0.25
0.50
107 92 85
3.44 0.80 0.95 0.27
%
Recovery organic
95
5.67 1.00 2.50 1.00
%
Recoverya in organic
3.50 2.49 4.49
4.00 2.90
Total Hg found after spiking
2.02 0.60
2.58
STP effluent
Organic Hg added
96 109
3.51 3.34 2.10 0.73
91 95 108
90 102 115 95
a Defined as the % total recovered mercury.
totai mercury in the system is then determined, using the normal digestion and reduction steps and read off a calibration curve done under the same conditions. The difference between total and inorganic mercury is the amount of organic mercury in the samples. Table VI1 gives the data for inorganic and organic mercury content of real as well as artificial mixtures. No attempts were made to analyze for organic mercury independently.
ACKNOWLEDGMENT The authors are grateful for the help received from many of the personnel of the US. Environmental Protection Agency, Region V, Central Regional Laboratory.
LITERATURE CITED K. K. S.Pillay. C. C. Thomas, Jr., J. A. Sondel, and C. M. Hyche, Anal. Chem., 43, 1419 (1971). V. I. Muscat, T. J. Vickers, and A. Andren, Anal. Chem., 44, 218 (1972). E. W. Bretthauer. A. A. Moghissi. S. S. Snyder, and N. W. Matthews, Anal. Chem., 46, 445 (1974). J. J. Bisogni, Jr., and A. Wm. Lawrence, Envlron. Sci. Techno/., 8, 851 (1974). C. T. Elly, J. WaterPollut. ControlFed., 45, 940 (1973). R. F. Overman, Anal. Chem., 43, 616 (1971). T. J. Rohm, H. C. Nipper, and W. C. Purdy, Anal. Chem., 44, 869 (1972). H. J. lssaq and W. L. Zielinski, Jr., Anal. Chem., 46, 1436 (1974). W. F. Fitzgerald, W. B. Lyons, and C. D. Hunt, Anal. Chem., 46, 1882 (1974).
(10) W. R. Hatchand W. L. Ott,Anal. Chem., 40, 2085(1968). (11) B. W. Baileyand F. C. Lo, Anal. Chem., 43, 1525 (1971). (12) T. B. Bennett, Jr.. W. H. McDaniel, and R. N. Hemphill, "Advances in Automated Analysis", 1972 Technicon International Congress, Vol. 8: Mediad Incorp., Tarrytown, N.Y. (13) P. D. Kluckner, "investigation of an Automated Method for the Determination of Total Mercury in Water and Wastewater", a report to the Chemistry Laboratory Water Resources Service, 3650 Wesbrook Crescent, Vancouver, British Columbia, Canada, 1973. (14) "Method for Chemical Analysis of Water and Wastewater", EPA Publication No. EPA-62516-74-003, US. Environmental Protection Agency, Office of Technology Transfer, Washington, D.C., 20460, p 118. (15) A. E. Ballard and C. D. W. Thornton, hd. fng. Chem., 13, 893 (1941). (16) S. Shimornura, Y. Nishihara, and Y. Tanase, Jpn. Anal,, 17, 1148 (1968): 18, 1072 (1969). (17) R. V. Coyne and J. A. Collins, Anal. Chem., 44, 1093 (1972). (18) C. Feldman, Anal. Chem., 46, 99 (1974). (19) M. H. Bothner and D. E. Robertson, Anal. Chem., 47, 592 (1975). (20) W. A. Moore, F. J. Ludzack, and C. C. Ruchhoft, Anal. Chem., 23, 1297 (1951). (21) J. F. Kopp. M. C. Longbottom, and L. B. Lobring, J. Am. Water Works Assoc., 64, 20 (1972).
RECEIVEDfor review March 21,1975. Accepted September 29, 1975. A.A.E. thanks Western Illinois University for an assignment on details to the U S . Environmental Protection Agency under the Intergovernmental Personnel Act of 1971, for the 1974-75 academic year. The mention of trade names or commercial products does not constitute endorsement or recommendation for use by the Environmental Protection Agency.
Gelatin Multicomponent Trace Element Reference Material D. H. Anderson,* J. J. Murphy, and W. W. White Industrial Laboratory, Kodak Park Division, Eastman Kodak Company, Rochester, N. Y. 14650
A new gelatln reference material containing 25 trace elements ranglng in concentrations from 27 to 62 pg/g was compounded and analyzed by 11 independent laboratories.
The feasibility of using gelatin, containing trace quantities of mercury, as a reference material was pointed out in 1972 ( 2 ) . Since then, we have shared our reference material with several laboratories. Their continuing interest in a multicomponent trace element system was the reason that a new gelatin reference material, TEG-50-A, was compounded to contain 25 elements. This new gelatin matrix has been evaluated so far by 11 independent laboratories. The availability of a stable organic reference material containing trace elements in known concentrations is desirable for the following reasons: method development, quali116
ANALYTICAL CHEMISTRY, VOL. 48, NO. 1, JANUARY 1976
ty control of analytical systems, and the need of such a material for laboratory cross-checking purposes. The reference material is not a substitute for recognized standards. However, TEG-50-A has been invaluable as a check sample in our laboratory for the determination of trace elements in organic substances by a wide variety of methods.
EXPERIMENTAL Solutions of the 25 elements were added to a gelatin solution and thoroughly dispersed before the solution was allowed to gel. The method of Anderson, Murphy, and White ( I ) which describes how a mercury reference material can be compounded from gelatin was followed and scaled up to accommodate a 2-kg batch. The elements added to the gelatin were in the acid, nitrate, or chloride forms. Ten grams of thioacetamide were added to the suspension to help prevent the volatilization of some of the elements.
Table I. Summary of Quantitative Test Data on the Gelatin Reference Material
Elements
No. of laboratories that participated in the determination of the element reported
Av value, I.cg/ga
Table 11. Summary of Laboratory Methodw Used t o Determine the Elements
Std dev, MIgb
Aluminum 4 53 ... Antimony 5 53 4 Arsenic 5 48 8 Barium 4 55 ... Beryllium 4 55 ... Boron 1 54 ... Cadmium 10 54 5 Chromium 10 56 9 10 49 5 Copper Gallium 3 57 ... 3 51 ... Indium 8 62 11 Iron 6 49 6 Lead Manganese 9 52 7 7 27 6 Mercury Molybdenum 6 55 7 8 52 4 Nickel Selenium 5 38 5 7 46 5 Silver Tellurium 1 50 ... 2 57 ... Thallium 2 46 ... Tin 1 49 ... Uranium Vanadium 4 50 ... 9 53 4 Zinc a I n determining the average, the Q test for deleting extraneous results was used (R. B. Dean and W. 3. Dixon, Anal. Chern., 23, 636 ( 1 9 5 1 ) ) . For Sb, Ba, In, Pb, Hg, Se, V, and Zn, one result’in each series was deleted before averaging. For Ag two results were deleted. b The standard deviation is given for each element when more than four independent laboratory results were averaged.
Elements
AA
Aluminum Antimony Arsenic Barium Beryllium Boron Cadmium Chromium Copper Gallium Indium Iron Lead Manganese Mercury Molybdenum Nickel Selenium Silver Tellurium Thallium Tin Uranium Vanadium Zinc
4 4
NA
X ray Color Fluor
1 2
3
3 4
OES
ASV
1 1
7 6 9 1 1 7
1 2 1 2
1
1
1
6 7
1
5
2
1 1
4 7 1 4 1
1 1 1 1
2 2
1 1 1
1 1 2
1
1 1
2
2 3 6
a Atomic Absorption (AA), Neutron Activation (NA),
Colorimetry (Color), Fluorometry (Fluor), Optical Emission Spectroscopy (OES)and Anodic Stripping Voltammetry (ASV).
source for environmental protection-related work has also been suggested. We would appreciate hearing from others who would like to participate in future studies involving gelatin as a reference matrix. Suggestions on combinations of elements in desired concentrations would be welcomed.
ACKNOWLEDGMENT RESULTS AND DISCUSSION Table I gives a summary of the analytical results obtained from the 11 laboratories. The majority of the data were collected on the “common elements” because they are normally part of each laboratory’s routine testing program. Table I1 gives a breakdown of the various quantitative methods used to determine the elements. Atomic absorption was the most widely used method except for the arsenic and selenium determinations. Special Uses of TEG-50-A. The reference material has been used t o study possible losses of arsenic, boron, mercury, and selenium during the wet- and/or dry-ashing of proteinaceous substances. I t has been suggested that TEG50-A be used as a carrier for adding trace elements to ecosystems to monitor toxicity effects. The use of the material to provide metals as well as a biochemical oxygen demand
We deeply appreciate the interest and efforts of all who made this report possible. We wish to express special thanks to the following who did the independent testing: Thomas B. Bennett, Jr., Environmental Protection Agency; Robert Brown, Accu-Labs Research; Marilyn Hendzel, Department of Environment; John D. Jones, University of Michigan; John Van Loon, University of Toronto; James N. Bishop, Ministry of the Environment; C. R. Cothern, University of Dayton; R. E. Jervis, University of Toronto; John F. Kopp, Environmental Protection Agency; and Douglas Mitchell, N.Y.S. Department of Health.
LITERATURE CITED ( 1 ) D. H. Anderson, J. J. Murphy, and W. W. White, Anal. Chern.. 44, 2099 (1972).
RECEIVEDfor review April 17, 1975. Accepted October 10, 1975.
ANALYTICAL CHEMISTRY, VOL. 48, NO. 1. JANUARY 1976
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