Document MdddgmpQdaLe2g3DZxOQOOka

To: From: Subject: CC: Dr. G. W. Beste Dr. R. C. A. Bock Mr. J. Cholak Dr. H. E. Hesselberg ETHYL CORPORATION Dr. R. A. Kehoe this COPY Dr. G. F. Kirby Inte r- Offi ce Dr. K. V. Kitzmiller Mr. W. R. Perdue Dr. S. O. Rue Mr. P. E. Weimer Mr. H. K. Ball R. L. Hudson LeadinAir Analysis NewYork Baton Rouge July 27, I960 We were pleased to receive your letter of July 22. It appears that we have a good number of problems before we have the solid iodine LIAmethodin the field, but I'msure we canworkthis out. What is of immediate concern to us is that the standard old LIAmethodis still being usedin California for TML inair, andIquote fromyour letter: "Therefore, there wouldbe nodifference at all inthe method used for taking TELinair andthe recommended methodfor this survey of taking TMLinair. At J. Cholak's suggestion our people were to take 8 cu. ft. reading every 10th sample. " Youfurther state that the above informationis based ona letter received fromA. H. Chenault, June 28, I960. Perhaps it wouldbe of interest to you, andother parties concernedwith this problem, to reviewthe facts as to the standard LIAmethodfor TMLin air versus the modified tentative methodwhichwe have developed andrecommended to be used until suchtime as the solid iodine scrubber method is available. As early as February 6, 1959, we reportedin theweekly letter to G. F. Kirby, andIquote: "Laboratory tests of the standardfield kit method for leadinair have showna serious error whenappliedto the measurement of TMLinair. The efficiency of recovery of knownamounts of TMLvapor is only 10to 25%under standardtest conditions". The above datawas later confirmed at our Detroit laboratories andis still essentially correct today. OnFebruary 18, 1959, we reportedina teletype to Dr. Kehoe essentially these same results, stating that the results wouldbe less than 25%of the true value, further pointing out that the reactionof TMLwithiodine is a slower reaction, and that several variables in the field kit are more critical for TML----such as sampling rate, iodine concentration, glass wool packing, andtemperature. t it 43r\ r %J \ j U ' N9569 2. OnFebruary 25, 1959, Dr. M. E. Griffing of our Detroit laboratories passedthe above informationto Dr. M. R. Barusch of the California Research Corporation, andfurther recommendedtohim: a. Use the scrubbers and solution recommendedin the leadinair kit. b. Use two scrubbers in series andanalyze their solutions separately. Consider anyanalysis suspect if the second scrubber contains more lead thanthe first. c. Use afine glass wool; make sure that adequate packingis used, andthat channelling does not occur. d. Use a flowrate of 0. 3 cu. ft. per minute for lowconcentrations of TML andof 0. 1cu. ft. or less for highconcentrations. The above essentially describes whatwe consider to be a modifiedtentative methodfor TML. inair, andwe have adequate datato prove that recoveries with this systemare in the 90%range. We have also considered other systems, such as 2normal iodine and 1. 5normal KIin one scrubber. Also, we considered the use of alcoholic iodine. Bothof these approaches were later abandoned, primarily because the solutions are difficult to handle andnot readily available inthe field except as bulk reagents. OnApril 7and8 onyour visit to BatonRouge, youwere told that the present LIAkit for TMLinair is not adequate andthat we wouldhave to use some modifications, suchas two scrubbers in series and lowsampling rates. It was at this time that we also informedyouthat we could collect andmeasure TMLquantitativelywiththe use of a solidiodine scrubber. Later this same month we provided Wil Hancockwiththe tentative fieldkit methodfor TMLinair using two scrubbers in series, standard reagents, anda sampling rate of not more than0. 3 cu.ffc. per minute, anda sample size of two cubic feet. InMayof this year we also suppliedA. H. Chenault the same method alongwith enoughbulk reagents for 400 TMLinair tests. Nowto review...........We have always maintainedthat the present LIAmethod is inadequate for the measurement of TMLinair andgives recoveries of less than 25%whenused at standard(0. 5to 1.0 cu. ft. /min. ) sampling rates. We have recommendedfor aninterimperioda methodusing two scrubbers in series and lowsampling rates, andhave adequate data to prove that this tentative methodgives approximately 90%recovery of TMLinair. We have amethod using solid iodine scrubbers whichwill give quantitative recovery of TMLin air. CPu u( o14 The problemhere, as youknow, is to find a supplier who canmanufacture these solid iodine scrubbers so that the scrubbers will not have anexcessive pressure drop. Finally, the newLIAmethod has beenwritten and submittedto the Journal of Analytical Chemistry, andwill shortly appear inpublic print. The-article contains datathat conclusively proves that our present lilAmethodis no good for TML, as well as a number of other organolead compounds inair. RLH/meb R. L.. Hudson