Document NE3M9378Xk83D26VV399qNqXD

Cincinnati, Ohio June 20, 19^5 Dr. C. B. Willoughby Chemical Department Experimental Station B. I. duPont da Kamour* and Co. Wilmington, Delaware Dear Dr. Willoughby Z foal that I cm* you an apology for not hairing at least acknowledged the receipt of your letter of January 22nd long before this I hare your last letter writ ten May 29th. During the past tee week* I hare been ao busy with calculation! it ea* impossible fas* me to write a suitable answer to your letter. It was very con siderate of you to forward the details of the bismuth separation prior to the publication of your paper. In looking through my file I find that I have lost the only copy of my letter to you dated January 7th. If you still have this letter, would It be convenient for you to send me a copy? y thanks In advance. You ask if we are still interested In the collaborative work. In spite of our apparent disinterest I must say that It is only the press of many other things which prevents us from working on this problem. We hope that you will continue to hold a place for the samples we hope to send you as soon as a favorable opportunity presents it self. We have reoently reoeived two reprints of articles appearing in Angew. Cham, during this year* It Is my Impression that these articles may Interest you, so that I send the titles In case you have not encountered then In your search of the literature. "Determination, of Minute Quantities of Lead by Electrolysis" Angew. Chess. Vol. Ip8 og.259, 1955 Dr. Albert Peeke, and Dr. Herbert Muller of the Institute of Hygiene (D!roctorj-Prof Dr. P Schmidt) Martin Luther University Halle - Wittenberg This paper is an answer to a criticism of the method by B. Behrens who particularly attacked the electrolysis step as yielding incomplete separation. / 2 Dr* willou :bby by Means of m Radio-aetivity Method, the Quantitative Analysts of Minute Quantities of Lead as Carried out by P* Schmidt and Co.Worker** Angew* Chew* Vol* 48 pg2ol, 195$ Dr* W* Messerscbmldk and Dr* 0* Fartler of the Institute of Physios (Dlreoton Prof* Dr* 0* Hoffmann) Martin Luther University Halle * Wittenberg This paper endeavors to show the completeness of the anodie deposition of lead during electrolysis by measuring the Oaasaa ray emanation of the daughter substance Thorium C" obtcl ned from Thorium B the radio active isotope of lead* They stress the advantage of the measurement of the Gammg ray emanation over that of the Beta ray emanation* Their eonoluslon Is that aa little as 0*03 mgs* to completely deposited during electrolysis* We have occupied a portion of our time In trying to establish the magnitude of the very small blanks encountered. In the preparation of samples for spectrographie analysis* At this writing we do not care to make a state* meat as to the resulte obtained* Mr* Cholak has tested the graphite electrodes you so kindly sent and found them very similar to some special graphite electrodes we have obtained from national Carbon Company at exactly the raise cost* The graphite electrodes used routinely fall to slum either the sensitive lead or bismuth lines* Their ooet in thousand lots 5/1ott x 12" is 7 oents each* The bismuth nitrate we have used in prepara tion of bissiuth solutions does not oontaln sufficient lead to give a speotrographle test* At present the bismuth in ternal standard Is a concentration of 1 mg* per 100 c.c. of solution as rejtdy for the arc* The small amount of lead capable of giving the line used in quantitation Is 0*000002 mgs* on the arc. During quantitation 0*002 mgs* of bismuth is present on the arc* This amount of bismuth is equivalent to approximately QOkl mgs* Bi(KOs)s*5HttO* We can calculate that the lead concentration of tne bismuth salt must be over 0*001$ before the lead line will appear* Concerning the use of blood findings as a diagnostic measure, X must repeat that the experience we have had does not permit us to rely solely on a blood analysis* I do not thick our data sufficient to answer your question concerning the lead concentrations in blood when the patient has an acute attack of plumb lam. The picture in the case of chronic plumbiam is certainly nothing so definite that one can rely on blood findings alone. Usually when the blood lead exceeds 0.15 mgs./lOO o*o* the urinary lead Is suffi ciently above the normal range and clinical symptoms appear which make It possible to diagnose the case. 5i 3 Dr. Willoughby Thor* la no datea available on the relation between load in tho blood and lead in the bonea under various conditions. Yea are of eourae familiar with Dr. Aub >a theory concerning the awbllisatian and deposition of lead but ho has not presented any data which would reweal such relation. Hr. Cholak and I were very much latereabed In your examination of the data and your resulting ocaenent. We agree that distilled water adds very little lead* our epeotro* graphic analyses show our double distilled water to contain leas than 0.002 mgs./llter. We do not think that the positive findings in samples 2,3,5 and 7 are duo to contamination* Wo have newer encountered a blood cample which did not oontaln load. Qualitative analyses on cample# deposited directly on electrodes and involving no treatment always show lead. We wish to do further work on this before we offer any positive explanation. At this time we have fouhd one fsotor about the quantitation whieh could easily account for the variation from .00i* to .006 but not for the 0008 found In sample 5* X do not know if we have compiled with your request for a reprint of Ur. Cholak*s paper. We are sending one under separate cover. Thank you for your continued Interest and hearty cooperation. Sincerely, FTtia ^redorlok fhamann 00601