Daniel W. Vomhof U.S. Customs Laboratory 610 South Canal Street Chicago, III. 60607
Analytical Chemists in the The U.S. Customs Service is the oldest Federal law enforcement agency; it is celebrating its 186th anniversary this year. The 2nd Act of the First Congress of the United States provided for the collection of customs duties by the Secretary of the Treasury. By 1799 laws establishing the tariffs on several commodities, defining the customs districts, listing the functions, and regulating the employment of customs officers had been enacted. As more commodities were included in the Tariff Act, it became necessary to obtain expert opinion on such questions as purity and composition. The Congressional Act of June 26, 1848, authorized the appointment of special examiners of drugs, chemicals, and other commodities. The first
Importer
Customs Agent
Other Agencies FDA. USDA. FTC
Laboratory
Figure 1. Origin of typical customs laboratory problem
special examiners were political appointments held by pharmacists and physicians. These special examiners were continued until the late 1870's when they were gradually replaced by chemists. In 1901 the Bureau of Standards was established in the Treasury Department. Its primary purpose was to develop a uniform set of weights and measures to be used by customs. The Bureau of Standards was transferred to the Department of Commerce in 1903 and later renamed the National Bureau of Standards. By 1900 customs had laboratories established in New York, Philadelphia, New Orleans, Chicago, and San Francisco. The purpose of the customs laboratories today is much the same as it was in 1848—the technical examination of imported merchandise to insure compliance with a variety of Federal laws, to detect fraud, and to provide general technical support for law enforcement activities. As a consequence, the customs laboratory activities are a combination of quality control, technical service, criminalistic, and analytical research and development. The commodities tested run the gamut from alabaster and alfalfa through human hair and marijuana to plastics and zinc. These commodities come from the importer, customs officials (inspectors, import specialists, special agents), and other Federal agencies as indicated in Figure 1. Because the staff of the customs laboratory is small relative to the quantity and breadth of work, it is essential that the analytical approach be used to obtain the maximum of information in the minimum of time. The general scheme employed is shown in Figure 2. Three problems are presented to show the scope and variety of customs laboratory activities. One involves marijuana and a possible conspiratorial relationship. The second has to do with a question of the tariff classifica-
228 A · ANALYTICAL CHEMISTRY, VOL. 47, NO. 2, FEBRUARY
1975
tion of a fruit juice, and the third problem involves determining whether an item is in the antique classification and consequently not subject to tariff. Marijuana Conspiracy
The first problem appeared when a customs agent brought two samples to the laboratory for examination. The first was plant material wrapped in a piece of red cloth taken from a suspect at one location, and the second sample was a sitar case found in the apartment of another suspect. The question was whether the marijuana in the possession of the first suspect came from the apartment of the second suspect. In other words, was there a conspiratorial relationship between the two suspects? Such a relationship is treated by the courts much more strictly than simple possession of marijuana. The approach taken by the chemist assigned to the examination of the two samples is outlined in Figure 3. Examination of the plant material under the microscope revealed the presence of characteristic cystolithic hairs on the plant fragments, as well as a few seeds having the characteristic veination of marijuana seeds. A few plant fragments were subjected to the Dequenois-Levine spot test which resulted in a purple chloroform layer, indicating the plant material was marijuana. This preliminary result was checked by analyzing the plant material along with a known sample of marijuana and of tetrahydracannabinol (THC) by thin-layer chromatography (TLC). The developed TLC plate showed that the plant material was indeed marijuana, both by the comparison of the "fingerprint" of the spots of the known marijuana sample and by the presence of the THC spot. Fragments of plant material found in the sitar case were subjected to the same tests and gave the same results, indicating that marijuana also was present in the sitar case.
The Analytical Approach Edited by Claude A. Lucchesi
U.S.
Customs Service
The question of whether the two seizures were in fact related was pur sued in two ways, a detailed study of the compositions of the marijuana found at each location and a careful comparison of the red cloth containing the plant material with the red fabric lining of the sitar case. The data ob tained in this phase of the investiga tion are indicated in Figure 3. Spot size measurements of the TLC plates indicated that the compounds cannabinol, cannabidiol, and THC were in about the same ratios in both samples. Next, portions of the two samples were both carefully ashed. The ash was then run on the emission spectrograph. Although this test is often more conclusive in showing dissimilarity, in this case, traces of two particular elements were found in both samples. The presence of these two elements had not been observed in a previous study of over 30 marijua na samples from several parts of the world. Thus, it was concluded that it was quite probable that all of the mar ijuana had originally been in the sitar case. The sitar case was lined with a red fabric from which a large piece had been cut out. This lining was similar in appearance to the cloth containing the plant material. Chemical examina tion showed that both fabrics were cotton. Both fabrics had the same density and the same number of threads per inch. The size of the plant wrapper was identical with that of the missing piece of case lining. Thinlayer chromatography showed the same pigment patterns in the red dye of the two samples. The probability of two samples hav ing so many characteristics in common and yet not being related is so slight that the inevitable conclusion was reached that the marijuana sample had originally been in the sitar case. The technical evidence supported the theory of a conspiratorial relationship
Definition of the Problem
Personal Observation
τ
Review of Customs Tariff Laws and Regulations
Formulation of General Analytical Approach
Select One or More Visual Microscopic Physical Properties Organic Analysis Inorganic Analysis Literature Search
Further Formulation of the Problem
X
Organic
Select One or More
Inorganic
TLC
Wet Chemical
IR
Metallographic
UV
Emission Spectrographs
GC
Atomic Absorption
Fluorescence
X-ray Diffraction
Wet Chemical
X-ray Fluorescence
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No Figure 2. General analytical process for typical problem ANALYTICAL CHEMISTRY, VOL. 47, NO. 2, FEBRUARY 1975 · 229 A
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TECHNIQUE
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RESULTS
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taric acid, and this was confirmed by thin-layer chromatography. Gas chromatography was also employed to quantitate the amount of glucose, fructose, and sucrose. The ratios of these three sugars to each other and to tartaric acid were in agreement with that normally encountered in such concentrates. The chemist concluded that the sample was indeed a natural grape juice which had not been concentrated to the usual degree. With this information the import specialist was able to make the appropriate tariff classification so that the correct amount of duty could be collected. The techniques used in solving this problem are depicted in Figure 4. " A n t i q u e " Belt B u c k l e
CONCLUSION
Plant material ir.. irwiHjuana w i t h common source cloth packnge came ftom srtur case
Figure 3. A p p r o a c h to identification of physical evidence in criminal conspiracy
Density
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ossible lartaric Acid
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Figure 4. Testing concentrated fruit juice
between the two suspects and was used by the government attorney to obtain convictions against the two sus pects.
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Tariff Classification of Fruit C o n c e n t r a t e
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Figure 5. Analytical process in e x a m i nation of metallic buckle invoiced as an tique 230 A ·
An import specialist submitted a sample of a viscous liquid invoiced as "grape juice concentrate" with a re quest to determine whether the com modity had been invoiced correctly. This information was required before the correct tariff classification could be made. The density of the liquid was about two-thirds that of most import ed grape juice concentrates. The re fractive index was also outside the range normally encountered. Thinlayer chromatography, however, indi cated a pigment pattern typical of grape juice. Gas chromatography showed the probable presence of tar-
A N A L Y T I C A L C H E M I S T R Y , V O L . 4 7 , N O . 2, F E B R U A R Y
1975
A tarnished belt buckle with the words "Wells Fargo" on it was pre sented to the laboratory by a port di rector who suspected fraud. He asked that the item be examined to deter mine whether it actually was an an tique. How does one show if a belt buckle is antique? The approach taken is shown in Figure 5. Customs regulations state that an item is an antique—and free of tariff duty—if it is over one hundred years old. The Wells Fargo belt buckle cer tainly looked like it could have been worn by a pony express rider. Under a low-power microscope, however, the patina and several of the scratches did not appear quite as they should have. They were a little too uniform, and it was decided that further testing was in order. Wiping the back of the buc kle with an organic solvent quickly re moved much of the tarnish. The con clusion was that the surface treat ment, at least, was much less than the required age. At this point, shavings of metal were removed from the back side of the buckle. Care was taken to obtain more than just a surface sam ple while not irreparably damaging the article in case it was genuine. Por tions of the sample were prepared for analysis by both emission spectrogra p h ^ and atomic absorption (AA) tech niques. The AA results showed a cop per-zinc ratio which was not typical of that employed in brass works in the 1850's. The emission spectrograph plate was quite interesting in that the presence of aluminum was indicated. Quantitation on the AA determined that the alloy contained almost 7 wt % aluminum. The presence of that much alumi num could hardly be due to an impuri ty. A review of the history of alumi num ascertained that it was not com mercially available prior to 1890. Thus, the belt buckle was not legally an antique, and the importer was lia ble for duty on the shipment. CIRCLE 36 O N READER SERVICE CARD •
