V O L U M E 26, NO. 5, M A Y 1 9 5 4 interference caused by the organic solutes is apparently due to their effects upon the nature of the ~ p m yentering the flame and their consequent hindering of the activation of the metal by the flame. Partial absorption of the radiation produced by the metal or partial dissipation of flame energy by the contaminant are other possible causes of the obwved effects.
813 effects more rapidly than it decreases flame inteneities m u d by metals. In cases where the chemical composition of the samples vary considerably, the procedure of compounding standard solutions is not practical. The compounding of standards is applicable only when one can accurately predict the composition of the samples. If the sample is viscous, the compound causing the viscosity must be used in making up atandmd8, since that particular compound will probably cause significant interferences because of factors other than viscosity. Indiscriminate use of substances in standards to approximate the chemical and physical characteristics of the sample is likely to result in gross errors. ACKNOWLEDGMENT
This work was financed in part b y a Frederick Gardner Cattrell Grant from the Research Corp. LITERATURE CITED (1) Berry, J. W., Chamell, D. G., and Barnes, R. B., IND. ENG. CHEM.,ANAL.ED.,18, 19-24 (1946). (2) . , Billa. C. E.. McDonald. F. G.. Niedermever. W.. and Sehwarts, M. C., ANAL. CKEM.; 21, 107&80 (1949):
Figure 13. Effec:t of Isopropyl Alcohol on Spray Particle; Size of a 0.5M Sucrose Solution Ata,mized into Flame W^ "..".-"I -^+L^-l .e ,,.retting " " ~ -yv LCL.sLa. l.lrU.lYY empirically for th e interferMmihla. ences of organic contaminants seen..7 1 , ~ - ~ ~thmref, ...-~ ...om, . " ,it appetL1S that the best method of eliminating such interferences encountered in actual analysis is to rcmove the interfering substance. dilute the 6amde until interferenee is neelisible. or compoundthe standard to approsimate the compositi&of the sample. Ai it is usually impractical or impossible to remove the interfering substance satisfactorily, it becomes necessary to use one of the other procedurefi. The dilution method is best where the metal is of sufficiently high canoentration t0 give accurately measurable resulk after dilution. Diluting decreases interference
(3) Brown, J . G.. Lilleland, O., and Jackson. R. K., Pmc. Am. Soc. Hmt. Sci.. 52, 1-6 (1948). . . 1530-3I (4) Conrad, A. L.. and Johnson. W. C., ANAL. C H ~ M22, (1950). ( 5 ) Fox, C.L., Jr., Ibid.. , 3 . 2 137-42 (1951). .~ (6) Gilbert, P. T.,Jr., Hawes. R. C.. and Beokman, A. u.. 1otu.. za, 772-80 (1950). (7) Hinsmrk. 0. N.. Wittwer, S. I+., and Sell, H. M., Ibid.. 25,320-2
(1953). (R) Inman, W. R., Ropers. R. A , , and Fournier. J. A,. Ibioiis employed in developing the chimni:Itogrnms. LITERATURE CITED
(1) Betts, K. H., and Leigh, lt. K., C'ajl. J . R~seavcit,28B, 514 (1950). (2) IJolomey, R. .I.,and Wish, I.., ,l. Am. Chcnr. S O C . ,72, 4488 (1950). (3) Cefola, AI., Andrus, W. SIi(~(~inli, B. It., and Isnowski, I,. K., Mikrochemie i'cr. M ochim. Acta, 35, 439 (1950). (4) Datta, S. P., Overell, 13. G . , aiirl Stack-Dunne. AI., .Yatnre. 164, 673 (1949). ( 5 ) Feigl. F,, "Qualitative ;\iinlysis by Spot Tests," g . 135, S e w York, Elsevier Publishing Co., 1947. ( 6 ) Huffman, E. H., and Beaufait, I,. J . , J . A m . Che?n. SOC.,71, 3179 (1949). (7) Reid, J. C., and Calvin, > I . , Ihid., 72, 2948 (1950). RECEIVED for rerieiv 1)w.enitrt.r 9, l ! l 3 , .ivcepted F'rbriiavy 19, 1954.
