OCTOBER, 1941

Applications of the Spectrograph to Toxicological Investigations*

CHARLES W. RANKINNew York State Police

INTRODUCTION

THE spectrograph has long proved its valuein forensic investigations of bullet traces,

paint analysis, etc. We have seriously doubted,however, its applicability to the study of metallictraces where much organic material was present,i.e., its application to toxicological investi-gations.

Perusal of the literature found it rather meagerso far as any work in English was concerned.Even in the German publications, most in-vestigators followed the pioneer methods ofGerlach' and concerned themselves with thal-lium, whose spectrum sensitivity is well known.

A brief review of toxicological literature in-volving the spectrograph is not amiss here.The writer first consulted Meggers and Scribner'sIndex to the Literature on Spectrochemical Analy-sis,2 and the Van Someren SpectrochemicalAbstracts,3 as well as the standard works ontoxicology such as Webster, 4 McNally, 5 andGonzales, Vance, and Helpern. 6 It was foundthat poisoning due to thallium usually involvedthe use of rat poison composed of thallium sul-phate with a fatty acid base, mentioned byRitterskamp, 7 Van Calker,8 R. Berge and H.P. Patzsch,9 G. Schrader and 0. Wiegand,10

* Presented at the Ninth Summer Conference onSpectroscopy and Its Applications at MassachusettsInstitute of Technology, Cambridge, Massachusetts,July 21-23, 1941.

1 W. Gerlach and W. Gerlach, Chemical and PathologicalApplications of Spectrum Analysis (Adam Hilger, London,1934).

2 W. F. Meggers and B. F. Scribner, Index to theLiterature on Spectrochemical Analysis (American Societyfor Testing Materials, 1939).

3 E. H. S. van Someren, Spectrochemical Abstracts(Adam Hilger, London, 1941), Vol. II.

4 R. W. Webster, Legal Medicine and Toxicology (W. B.Saunders Company, Philadelphia, 1930).

5 W. D. McNally, Toxicology (Industrial Medicine,Chicago, 1937).

' T. A. Gonzales, M. Vance and M. Helpern, LegalMedicine and Toxicology (D. Appleton-Century, NewYork, 1940).

7 P. Ritterskamp, Samml. Vergiftungsfallen 7, 201-204(1936).

8 J. van Calker, Arch. f. Gewerbepathologie und Gewer-behygiene 7, 685-91 (1937).

9 R. Berge and H. Patzsch, Deut. tiertartzl. Wochs. 43,20-21 (1935).

'G. Schrader and 0. Wiegand, Samml. Vergiftungs-fallen 7, 135-138 (1936).

Schneller," Gerlach, Rollwagen, and Intonti. 2

A case involving thallium poisoning occurredin this country recently, in which five deathsresulted in a family of seven taken ill."3 In theanalysis, approximately 0.15 gram of eachnecropsy specimen was burned on high puritygraphite electrodes in a 110-volt, d.c. arc operat-ing at five amperes. Thallium was found inmany body parts.

Gerlach,' Van Calker,8 G. Schrader and 0.Wiegand,' 0 mention cases where arsenic wasfound, but no quantitative results are given.The high frequency spark method is usuallyemployed.

METHOD

We use the spectrograph both as an analyticaland as a survey instrument. Toxicological analy-sis for alkaloids is a long and tedious process but,nevertheless, one that must be carried out.Use is made of Autenrieth's modification of theStas-Otto method, which depends upon theconversion of alkaloids into tartrates and thesubsequent liberation with ammonia or otherbases or acids. The alkaloids thus liberated areseparated by the use of many solvents immisciblewith water, such as ether, chloroform, and others.The solvent extracts are evaporated and theacid and basic residues are further purified byredissolving in dilute hydrochloric acid, filteringand extracting the filtrate as before. To thesefiltrates specific alkaloidal tests are applied.

In order to corroborate the chemical findingsas much as possible in all toxicological analyses,we prepare each sample of the various organs bythe Hess-Owens'4 method. In this procedure0.4-g samples of test material are treated in a30-ml Kjeldahl flask with 1 ml of concentratedsulphuric acid and heated on a sand bath heatedwith gas burners. When charring is complete,

X1 J. Schneller, Deut. Zeits. ges. gericht. Med. 25,223-30 (1935).

12 W. Gerlach, W. Rollwagen, and R. Intonti, Virchow'sArch. 301, 588-601 (1938).

13 J. B. Neal, E. Appelbaum, E. Gaul, and R. J. Masse-link, N. Y. State J. Med. 35, 657-659 (1935).

4 T. M. Hess, J. S. Owens and L. G. Reinhardt, Ind.Eng. Chem. Anal. Ed. 11, 646 (1939).

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nitric acid is added until the solution becomeswater clear, denoting complete oxidation. Ifthe sample is particularly difficult to oxidize,a few tenths milliliter of concentrated per-chloric acid is added. The solution is thenevaporated to dryness and, when cooled, oneml of concentrated nitric acid added. Evapora-tion almost to dryness next takes place, carebeing taken not to over-heat the mixture. Theresidue is taken up in 0.4 ml of a 2N nitric acidsolution containing the spectroscopic buffer andthe internal control elements.

Of course, if we obtain negative results in theform of no metallic elements present, this doesnot indicate the absence of alkaloids-on theother hand, traces of the toxic metallic elements,if found, will direct further analysis and willconfirm the chemist's findings.

APPARATUS

Chiefly because of its conservation of materialwe have employed the condensed spark as ameans of excitation. However, since quantitativeresults are sometimes needed, we have modifiedour original apparatus by using a Feussner"5

circuit. A transformer of 15,000 peak voltagecharges a condenser which discharges through aseries network comprising a synchronous inter-rupter, a resistor, and inductance and the samplegap. Their constants are as follows: Condenser,0.005 f; inductance, 500 microhenrys; resist-ance, 0.5 ohm; interrupter, a 3600 r.p.m. G.E.synchronous motor. It was found necessary touse the value of the inductance given in orderto make the 3176.5 spark line of lead disappearcompletely. A variable resistance of 100 ohmsis in series with the primary of the transformer,which allows a variation in the r.f. currentusually kept constant at 2 amperes. This re-sistance also sharpens the point at which ther.f. circuit is synchronized to peak voltage.

ARSENIC

On December 1, 1940, an elderly farmer inNew York State died under what appeared to benormal circumstances. However, soon after hisdeath, rumors were circulated to the effect that

15 0. Feussner, "Technic of spectrographic analysis,"Arch. f. Eisenhuttenwes. 6, 551 (1933).

his wife had poisoned him. Needless to say theserumors found their way to the ears of the StatePolice, and in order to satisfy themselves as wellas stop the ugly rumors, criminal investigationwas started. Six weeks after burial the body wasexhumed, and the organs, samples of embalmingfluid, and soil from the top of the grave were sentto the laboratory. One-half gram samples of theliver, stomach wall, and stomach contents wereacid digested as outlined previously. Meanwhile,our chemists found strong evidence of arsenic inpreliminary Reinsch test.6 In this test theorganic material is finely ground and cooked withdilute hydrochloric acid in which a small pieceof arsenic-free copper strip has been placed.Antimony, arsenic and mercury, if present, forma coating on the copper strip. To make the testmore specific, sublimation of the deposit isperformed; the coated copper is placed in a glassreduction tube sealed at one end, and the tubeheated and then examined under a microscope.Characteristic globules will appear if mercuryis present, or, as in this case, examination of thetube showed crystals of arsenic trioxide sub-limate. If arsenic be present in the form ofarsenates, a deposit will form readily; however, ifpentavalent arsenic is suspected, it is wise totreat the material under investigation with alittle sodium sulphite to reduce the arsenic tothe arsenous (trivalent) form; or one may adda few crystals of ferrous sulphate, and the coat-ing on the copper will appear in a short time.However, no lines of arsenic were found in thespectrograms of the ashed samples. The Gutzeit"7

test, a modification of the classical Marsh"s test,for arsenic was then performed, and the quantityof arsenic present was found to be of the orderof 150 to 190 milligrams per kilo, a result con-firmed independently by the Bender Labora-tories of Albany, New York.

Since, theoretically, the copper in the Reinschtest is coated with an alloy of arsenic and copper,a new Reinsch sample was prepared and thecoated copper spectrographed directly in the d.c.arc. The result is shown in Fig. 1. Sample number1 is arsenic trioxide, reagent grade; samplenumber 2 the Reinsch copper coated with the

16 J. f. prakt. Chemie 24, 244 (1841).17 Pharm. Ztg. 24, 263 (1879).18 London Med. Gaz. 18, 650 (1836).

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FIG. 1.

arsenic from the liver sample; and samplenumber 3 a copper sample known to contain,by previous chemical analysis, 0.0018 percentarsenic. The copper used in the Reinsch testhad been previously shown to be spectrograph-ically free from arsenic.

Various estimates are given in the literatureas to the lowest concentration of arsenic thatmay be detected spectrographically. Theserange from 0.03 percent' to 0.001 percent.20

The latter range would amount to 10 milligramsper kilo, which is the amount usually found inthe hair and bones in arsenic poisoning cases,and nowhere near the gross amount found in theliver and other organs, which may amount tobetter than 200 milligrams per kilo.

Field investigation proved that this was not acase of homicide but rather suicide; the methodwas arsenic poisoning.

LEAD

The greater sensitivity of the spectrograph tolead in comparison with arsenic was shown in arecent case involving the malicious poisoning ofa valuable cow. The liver was sent to the labora-tory some two weeks after removal. A sample wasashed in the usual manner and a spectrographicanalysis was undertaken of this, as well as ofsome suspected powder. Lead showed up clearlyin the spectrogram of the ashed sample, butonly in the powder was there any indication ofboth arsenic and lead. Once again the Reinschtest was applied and the arsenic coated copperstrip burned completely in the d.c. arc. Thearsenic lines 2288 and 2349 now appeared. Thepowder was found to contain lead arsenate to

19 D. M. Smith, Metallurgical Analysis by the Spectro-graph (British Non-Ferrous Metals Research Association,1933), p. 94.

20 E. K. Jaycox and E. A. Ruehle, Proceedings of theSeventh Conference on Spectroscopy (John Wiley and Sons,New York, 1940), p. 12.

which sodium chloride had been added, probablyto serve as a "salt lick."

The detection of lead in whole blood can bedone directly. A few drops of blood are dried inthe electrode which should be spectrographicallypure graphite. In a case in question, two men,painters, showed many evidences of lead poison-ing. However, neither patient was found to giveevidence of basophilic stippling of the bloodcells, which is characteristic, although notspecific, evidence of lead poisoning in chroniccases. Definite evidence of lead however wasfound spectrographically. This investigation wasnot of a criminal nature, but merely to aid thephysicians of a local hospital in their diagnosis.

BARIUM

In a previous paper 21 the writer mentioned acase of animal poisoning in which barium wasreadily detected by ashing the meat directly inthe spectrographic arc. This poison is rare inspite of the number of "barium meals" given forfluoroscopic and x-ray studies.

PHOSPHORUS

Since organic phosphorus is invariably presentin the intestinal contents, its spectrographicdetermination must be based on the increaseddensity of the phosphorus lines if the element ispresent in excess. In one case analyzed candyfudge was so impregnated with yellow phos-phorus that, when the heart-shaped Valentinecandy box was opened, the characteristic garlicodor was unmistakable. Phosphorus is sometimespartially oxidized in vivo. A six-year-old childof poor circumstances ate some refuse from adump heap where she had been playing withother children. The child was taken violently

21 C. W. Rankin, Proceedings of the Sixth SpectroscopyConference (John Wiley and Sons, New York, 1939).

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ill that evening and died early next morning.The vomitus when ashed and spectrographedshowed much phosphorus present. The stomachcontents and the intestines gave only a faintreaction.

MERCURY

For the detection of mercury we have foundthat best results are secured by using a gaseousdischarge tube illustrated in Fig. 2. This tubewas designed from one used by Pfeilsticker"2

for the determination of certain halogens. Theorganic matter is destroyed by the methodalready outlined,'4 and then the lower copperelectrode of the tube is dipped for about one-half inch in the concentrated solution and con-nected to the positive side of a battery, thenegative pole of which is connected to a spiralplatinum anode. Within five minutes all of the

FIG. 2.

22 K. Pfeilsticker, "Spektralanalyse der Halogene undanderer schwer anregbarer Nichmetalle," Spectroch. Acta1, 424-36 (1940).

mercury will be deposited on the electrode, whichis then placed in the discharge tube, the pump isthen started until the pressure in the tube isfrom 10 to 25 mm of Hg. The tube is excited withthe Feussner condensed spark arrangementpreviously described.

With such a set-up the mercury line 2536.5A ispresent with test solutions of mercury of 1 partin 100,000,000. When the mercury is presentin toxic quantities 4358.3; 3554; 3650.1; 2847.7,and 2536.5 all are present.

CONCLUSION

In conclusion, it is important to note that inscientific criminal investigation one cannotfollow any standardized spectrographic analysis.Evidences submitted for spectrographic analysiswill vary from one-half cc of blood to a four-pound liver, sometimes in good condition,more often badly decomposed. We rarely getpure samples-contamination is a big factorwhether it be in the form of embalming fluid or incases of animal poisoning-pieces of grain, hay,soil, etc. When vomitus is scraped from theground or recovered in a feed box, we usuallyhave about 90 percent contamination and 10percent sample. Under these circumstances, wecannot follow any definite procedure, and eachcase, therefore, receives slightly different treat-ment. We do not know what limitation can beplaced upon the spectrograph since literaturedoes not reveal much recent research on criminalinvestigation. However, it is our sincere beliefthat, in the near future, the spectrograph willbe used for toxicological analysis in criminalinvestigations to reveal traces of the halogens,alkaloids, etc.

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