Analytical chemistry and the effectiveness of food ... - ACS Publications


Analytical chemistry and the effectiveness of food...

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Aaron J. lhde University of Wisconsin Madison, 53706

Analytical Chemistry and the Effectiveness of Food Laws

Consumer protection agencies such as the Food and Drug Administration have been the targets of increasing criticism for their failure to deal effectively with the enforcement of the laws under their iurisdiction. The basis for such criticism is complex. It is easy to suggest that the fault lies in the inefficiency and defensiveness of bureaucracies, in unsatisfactory financing by Congress, in timidit y to act energetically in the face of producer group pressures, or in the time lag between the institution of fraudulent practices and the detection of such acts by the regulatory agency. All of these factors are unquestionably involved. An additional factor which has received little attention in public criticism has been inadequacy of the analytical art. A survey of the history of food regulation reveals that early laws dealt with frauds which were recognizable on the basis of sensory examination: visual appearance, taste, odor. feel: more rarelv" on . ohvsical - measurements. such as short weight or volume. Very rarely was reliance placed on chemical tests. Perhaps the best example of the latter was the practice of Roman housewives to test the genuineness of vinegar by pouring a few drops on the earth. In contact with the calc&eous soil of Rome.. eenuiue vineaar showed a vigorous effervescence; diluted vinegar showed little or no reaction with the soil. Since the mineral acids were not known a t the time, the substitution of sulfuric acid for acetic was not yet a problem. However, such tests based on chemical reactions were rare indeed and it is not surprising that such laws as were in effect dealt with violations that could be exposed without denendence on scientific measurements. As late as 1820 when Frederick Accum published his famous "Death in the Pot" his exposures were based more largely on court records than upon chemical analysis (IJ. Nevertheless, the power of the chemistry of his day to expose certain frauds is impressive: sulfuric acid sold as vinegar, copper salts used for coloring pickles, vermillion (HgS) used as a coloring agent in candy, the adulteration of vermillion itself with red lead (PhsOn). A generation later the frauds had apparently become more widespread rather than being curtailed. The reports of Arthur Hill Hassall in.The Lancet during the 1850's showed little advance in chemical sophistication over the techniques used by Accum hut Hassall made extensive use of the microscope. By comparing the microscopic appearance of genuine tea, coffee, meal, and starch with that of standard adulterants such as floor sweepings, chickory, dried leaves of trees, and powdered minerals he was able to reoort widesnread adulteration of foods. His chemical tests showed fukher that all 49 samples of bread examined contained alum: onlv four of 28 samnles of Cayenne pepper were pure-13 contained red lead and one contained vermillion; nearly all samples of candy were colored with lead chromate, vermillion, red lead, copper arsenate, white lead, or gamboge (2). The exposures published in The Lancet between 1851 and 1855 led, in the latter year, to the creation by ParliaPresented before the Division of History of Chemistry s t the 166th Meeting of the American Chemical Society, Chicago, Illinois, August, 1973.

ment of the Select Committee on the Adulteration of Food (3). Following its recommendations, Parliament passed a "Sale of Food and Drink Act" in 1860 (4). The act ~rovidedfor the aonointment of nublic analvsts. .. " . for prosecution of offenders, and for fines not exceeding f 5 . The act was a dismal failure, a s was predicted by William Crookes in his Chemical News (5). Appointment of public analysts was not mandatory and only a few municipalities chose to fill the position. When analysts were appointed they were generally medical men rather than chemists, a practice which Crookes attacked repeatedly. In actuality, it perhaps made little difference since chemical analysis of foods was scarcely equal to proving the presence of any except the grossest of adulterants. In addition, the act was so feeble in its legal aspects that few cases were successfullv ..nrosecuted. Public discontent, coupled with the editorial criticisms bv Crookes. forced Parliament to make a substantial amendment' in 1872 (6). The amendment raised penalties for the first offense to f50 and made the appointment of public analysts mandatory when voted by the local government Board. This resulted in a substantial increase in activity hut few results. The public analysts now had sufficient court experience to recognize inadequacies in the law as well as in their own professional capacity to recognize adulteration and present a persuasive case in court. It was becoming evident that Crookes had been right in arguing that medical experience was not enough, that successful enforcement required the introduction of evidence based on the competent application of chemical knowledge. More and more, the position of public analyst was filled from the rather limited pool of trained chemists, most of them teachers, or by medical men who had hothered to gain competence in chemistry. Another Parliamentarv Committee was created in 1874 to study the problem of iood and drug adulteration (7). Its report called attention to uncertainties among health officials and public analysts regarding the nature of adulteration. The report further lamented the inexperience and conflicting decisions of the analysts. Finally, it concluded that existing law was seriously deficient. In the meantime the analysts themselves swung into action. Two public analysts for London, Charles Heiscb and G . W. Wigner, issued an invitation to their counterparts in London and outlying areas to meet on August 7, 1874. Twenty-seven analysts attended. Resolutions were passed regarding training and qualifications of puhlic analysts, the refereeing of disputed positions, the examination of tea. the labelline of mixtures. and the formation of a perm;nent associacon of public' analysts (8). Details of the meetina were reported bv William Crookes in Chernical News fa; August i4, 1874. The last resolution was implemented on December 1, 1874 when 17 public analysts met in London to found the Society of Public Analysts. Dr. Theophilius Redwood, Public Analyst for Middlesex and professor of chemistry to the Pharmaceutical Society, was elected president; A. H. Hassall and James A. Wanklyn were vice-presidents. The new society also established suggestions for definitions of adulterations, and for standards or limits. For Volume 5 1 , Numbers. May 7974

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several years the proceedings of this and later meetings were published in Chemical News. Crookes, although not technically a public analyst, was elected a member a t the first regular meeting on February 5, 1875. A new hill dealing with the Sale of Foods and Drugs was debated by Parliament in 1875, being passed in midsummer. Royal assent was granted on August 11. The Society of Public Analysts was a significant force in bringing about passage by the House of Commons with favorable amendments, and in seeing it through the House of Lords without serious emasculation. Two members of Parliament who bore heavy responsibility for passage of a strong act were the chemist Lyon Playfair, Liberal M. P. for the Universities of Edinburgh and St. Andrews, and Charles Cameron, M. P. for Glasgow. Both were elected honorary members of the Society of Public Analysts for their role in Dassaee of the act. Prominent chemists who were voted honorary membership were Frederick A. Ahel, Edward Frankland. William Odling, and A. W. Williamson. While these men' were active in bther fields they all showed an interest in food chemistry and helped advance the prohlems of the Society through their prestige (91. By the end of 1875 the publishing arrangement with Chemical News proved unsatisfactory and the Society members resolved to form their own monthly journal under the editorship of G. W. Wigner, a public analyst and the operator of chemical consulting fiim in London. The first number of The Analyst appeared in March, 1876 .

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The need for stringent food and drug laws was acute. Commercial fraud was widespread in an England which bad undergone a rapid change in population patterns in connection with the extensive industrialization which had taken place during the nineteenth century. Residents of the large cities were dependent on a food supply which came from great distances and moved through many hands. But the passage of laws was not enough. In order to obtain convictions of dishonest businessmen it was necessary to establish evidence of fraud. Here the skill of the analvst was taxed to the utmost. ~ i o chemistry d was still in a rudimentary stage in 1875. Organic chemists had established the presence of such major components as fats, carbohydrates, and proteins, but there was still little systematic knowledge regarding the distribution of these components in most foods. This was the task of the analyst but he was hardly equal to the challenge on account of the lack of analytical methods suitable to the problems involved. The next three decades would see significant changes growing out of practical pressures faced by a group of public servants with only modest talents, men such as Alexander Wynter Blyth, Alfred Henry Allen, Otto Hehner, and James Alfred Wanklyn (11). Particular attention was concentrated in the early years on the adulteration of milk, butter, lard, beer, bread, coffee, tea, and flour. This same pattern is evident in parallel problems being explored in Germany, France, and the United States. It was during this period that there were developed the analytical indices for fatty oils (saponification or Koettstorfer numher, iodine number, ReichertMeissl numher, Hehner number); the color tests for oils used in adulterating valuahle oils (Halphen test for cottonseed oil, Villavecchia test for sesame oil, the Renard test for peanut oil); and various tests for detection of chemical preservatives such as formaldehyde, borates, henzoates, sulfites, and salicylates. By the end of the century, analytical chemistry was almost equal to the prohlem of controlling the characteristic forms of gross adulteration of food. The pages of The Analyst provide a running account of the analytical problems and the steps being taken to resolve them. Members of the Society were also publishing widely valued texts on food analyses. The foods part of Blyth's "Manual of Practical Chemistry" 296

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(1879) was expanded in the second edition of 1882 and issued in two separate hooks as "Foods, Their Composition and Analysis" and "Poisons, Their Effects and Detection." The fifth edition of the foods volume was published in 1903 under joint authorship with his son, A. Wynter Blvth. Jr. Even more important was A. H. Allen's "Commercial Organic ~ n a l ~ s i s which ," appeared in 1879 and became a veritable bible for food analysts. Substantial expansion of Allen's treatise occurred with each successive edition. It was continued after his death in 1904, the fifth edition in ten volumes being edited by Samuel S. Sadtler, Elbert C. Lathrop, and C. Ainsworth Mitchell and puhlished between 1923 and 1933. In the United States a somewhat belated but parallel development was taking place. It differed from the British movement in that the stimulus arose very largely out of agricultural problems but the ultimate result would figure heavilv in the field of food reeulation. Agriculture was still the principal occupation of the American po~ulationin 1870, but bv then the older agricultural re&ns, such as those in the South and in the Northeast were suffering from depleted soil fertility. Chemical fertilizers were taking on an importance which would grow, decade by decade. But farmers soon found themselves spending their income for commercial fertilizers of indifferent quality. They turned to their governments for protection. The agricultural experiment station movement of the 1870's and 1880's was a response to the demand. Chemists associated with such stations spent much more time on the analysis of commercial products than on original agricultural research. The same pattern was present in the U.S. Department of Agriculture which had been created in 1862 and was growing rapidly in stature (121. When Harvey W. Wiley became Chief of the USDA's Division of Chemistry in 1883 he was already well known as State Chemist of Indiana. He differed from most state chemists who were concerned primarily with fertilizer analysis. European study had acquainted him with the polarimeter a t the Berlin laboratory of public hygiene. He brought an instrument to America where it served him well in studies on sugar producing plants such as cane, beets, and sorghum. His studies also revealed widespread adulteration of syrups sold on the American market. Commercial glucose, which Wiley considered a perfectly good food when sold as such, was finding its way into honey, cane molasses, and maple syrup, thereby perpetrating a fraud on the American consumer (131. Wiley's concern regarding adulteration of syrups quickly extended to other foods and food analysis became a major activity of the Division of Chemistry. In 1887 Part 1 of Bulletin 13 was issued by the Division. It dealt with dairy products. There would be nine additional parts to Bulletin 13 by the time the studies were completed in 1902. One of Wilev's first moves as chief of the Division of Chemistry wasto join the other state, municipal, and federal chemists to form the Association of Official Agricultural Chemists, commonly referred to as the A.O.A.C. These men knew from experience that the reliability of methods used for the analvsis of amicultural products left much to he desired. They set out remedy the matter by deleeatine - - analvtical studies of particular methods to a team of analysts, working independently of one another. When a method was developed to the point of apparently giving reliable results, samples of known composition would be prepared and made available to officials who were developing the procedure. Each would carry out the analysis, then send the results to the official who sent out the n r e ~ a r e dsamdes. If evervone agreed on the analvsis, it wbuld be presented to the membkship for approval as an "Official." or in some cases. "Provisional" method. If results werd not in agreement; further studies would he instituted or the method abandoned. Approved methods

were incorporated into Bulletin 107 of Wiley's agency, now known as the Bureau of Chemistry. The bulletin, under the title "Official and Provisional Methods of Analysis" went through a succession of revisions up until 1920 when it appeared in book form as "Official and Tentative Methods of Analysis of the Association of Official Agricultural Chemists," published by the Association rather than by the Bureau of Chemistry. Revised editions have been published a t approximately five-year intervals. The "Methods" of the A.O.A.C. provided a source of reliable methods which not only had the confidence of analytical chemists but were able to stand up under the withering cross examination of trial lawyers. Despite the excellence of input into analytical chemistry by such agencies as the Society of Public Analysts (since 1907 the Society of Public Analysts and other Analytical Chemists; and since 1954, The Society for Analytical Chemistry), the A.O.A.C., and counterparts in other countries, food law enforcement continues to be bandicapped by deficiencies in analytical chemistry. Two examples will be examined briefly. There are many more. When lead arsenate spray residues on fruits and vegetables became a matter of public concern in the 1920's. there were methods for measuring the amount of arsenic present in a biological material but no satisfactory method for measuring traces of lead. Arsenic, used as a poison since antiquity, had had the attention of toxicologists for a century and methods such as the Gutzeit and Reinsch tests had been adapted for quantitative measurements. Almost reluctantly, in the face of opposition from the fruit growing interests, the Bureau of Chemistry began making seizures of arsenic-containing fruit in 1925 (14). In order to establish a sounder position regarding its actions the Bureau of Chemistry, soon to become the F w d and Drug Administration, sought the expert judgment of a committee of foremost toxicologists in 1927. This committee endorsed the position of the regulatory agency hut pointed out that the hazard from lead, a c&nulative poison, was undoubtedly greater than that from arsenic (15). Methods for determination of traces of lead on organic material were inadequate in 1927. The best procedure, which involved ashing the fruit, dissolving lead from the ash, precipitating the lead as chromate, and titrating for chromium, took three days of an analyst's time. This was obviously not a practical approach to policing the lead residue problem. Since arsenic was determined rapidly by the Gutzeit method, the Food and Drug Administration hoped that lead might be controlled automaticaIly by controlling the arsenic residue. Since lead and arsenic are present in lead arsenate (PbHAsOJ in equiatomic amounts, an arsenic tolerance of 0.01 grainsllb (1.3 ppm, as AszOa) should automatically limit lead to approximately 0.02 grainsllb. Such reasoning however, proved unreliable in practice (161. Weathering and washing left lead residues in excess of those predicted from stoichiometry. Hence, it became necessary to develop a rapid method capable of measuring lead directly. It was only in 1933, after extensive studies on various titrimetric, electrometric, and colorimetric methods for traces of lead, that the Food and Drug Administration undertook enforcement of a lead residue tolerance of 0.02 grainsjlb on fruit. By now, FDA chemists had developed a rapid method for determination of both arsenic and lead on the same sample. After digesting the sample with acid, the arsenic was distilled off as the trichloride and titrated with hromate. The pH of the residual solution was adjusted to 2.8-3.5 and the lead precipitated as sulfide, filtered, redissolved, and then precip-

itated as lead chromate. The chromate was redissolved and titrated with iodine (17). Subsequently the lead determination was further modified to utilize dithizone as a reagent for colorimetric measurement of lead (18). A repeat of history occurred around 1950 when the Food and Drug Administration was faced with the problem of residues of DDT and other chlorinated hydrocarbons. The analytical crisis was even more critical than it had been with lead. In this case there had suddenly been introduced into agriculture a host of compounds which were completely unlike any substances of previous analytical simificance. Thev were sufficientlv effective as insecticiYdes and quickl; displaced the traditional arsenicals for most common uses. At the time of their introduction they were considered comparatively harmless to higher animais and man; hence, there appeared to he no concern about residues and there was, a t first, no urgency in the development of analytical procedures. Fortunately chromatography, particularly vapor phase chromatography, had reached a stage of development by the early 50's that the problem could be attacked from this direction. Nevertheless, there was a period of development similar to the lead episode during which confidence in analytical methodology was lacking and during which effective enforcement was not possible. Acknowledgment

The financial support of National Science Foundation Grant No. GS 27505 is gratefully acknowledged. I am also indebted to Drs. Robert DeKosky and James Whorton for first calling attention to some of the facts developed in this paper. Literature Cited . .

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9, 4 2 b 524-6, 581-4 118531. ~ h many o articles of Hassall in Ths ~ o n c i w e r e eollrcted in "Food and k t % Aduft~mtlons."London. ISSS. pp 161-4. 467-9. 6W21. 131 Blyth. A. W.. "Foads. Their Composition and Anahsir." 4th. Ed., London. 1896. &U-25. I41 Ref. (31. pp 2627. Also see Filby. F. A,. "A History of Food AdulteraSon and Anslvsir." London. 1931 (which has a summarv of the Act 123 and 24 Victoria. ~ap..841together&h a part of the terton pp. 264-2451. 151 Crmkep. W.. Chemical News. I. 121. 229 il8C3Ol. A study of Cmkes' role in the issue in reported by DeKaky. R. K., "Tho Scimtifie Work of Sir William Cmakes."PhD Oinaertstion. Univanify of Wiscannin. 1972. pp. 155-161. 161 Fllbv. F. A,. Ref. (4). o 245: Blvth. A. W.. Ref. (31, .on. . 2628. 171 Ref..(31, pp 28-29. 181 Dyer. B.. and Mitchell, C. A,. "Tho Saciety of Public Analysts and other Anslytieal Chemists. Some reminiscenes of its first fifty years, A review of its activitis,"Londan, i932.pp. 1-6. 191 Ref. (81. pp 6 7 . For provisions of the Act see Ref. (3J, pp 29-32 and Filby, F. A,. Ref. 141. PP 245-247. I101 Ref. 181, pp.9-10. I111 For brief biowphier of those and other public analysts of the early period see Ref.

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1121 For information on the agicultural experiment atation movement in the U.S. see True.A. C.. "A Kintory of Agiculfursl Experimentation in the United States. IM17-L925."U.S.Depf.Ag., Mkc. Pubf.. 251. Washin&on, 1931. (131 Wiloy, H. W.. ''An Autobiography." Indianapolis. 1110, pp. 156185: AnderSO". 0. E.. Jr.. T h e Health of a Nation, Harvey W. W i b and the Fipht for P u r c F d , " Chicaqo. 1958. pp. 32-66. 1141 U.S. Depf. of Amiculturo, Bureau of Chemistry, Service and Regulatory Announcementr. Notice of Judgment No. 13936. For a full study of the Bureau's reaction Lo spray residues see WhoMn, J. C., Bull. Hist Medicine. 45, 219-41, or more fully in Whonon. J. C., "Insecticide R s i d u e ~on Foads as a Publie Health Roblem: 1869-1935." Ph.D Dissertation, Uniuenity of Winconsin, 1969. p s 109-119. The M h m n dissertation has been rewritten for early publication by Princeton University Press. 1151 ~ u n t R.. . "Report af conference a t ~ u r e a uof chemistry. ~ a n u a r y3. 1927, - h e ords F d and Drug Adm.. General Spray h i d u e File, 1935. Natl. Remrds Center. The full text of the Report has been repmdueed in the Whorton di-*ation. Ref. (141, pg 123-4. I161 Pearee. G. W., and Avenr, A. W.. J Eeon Entomology, 31.594-7 119381. 1171 Wichmann. H. J.. and Murray. C. W.. "Method for Determination of Ancnie and Lead on Fruitl and Veeetablea." Records FDA. l a s d Methods of Analysis File, (May 271. 1933, NRC. KG88 Relevant published information on these studies is in Wichmann.dal..JAr~or. Ol/iciaiAei. Chemirtr, 17.108-135119341. 1181 Clifford. P. A.. and Wichmsnn. H. J.. J. Asroc. Olliaol Agr. Chemists. 19. 130156119161.

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