2.1. Samples tested with the EVA films

The following items were examined with the EVA technology (Table 1): an Abercrombie & Fitch (A&F) sole leather medicine case from about 1911. Objects found inside the medicine case and tested included a glass vial of opium tablets; an article torn from the September 1911 issue of the American Journal of Clinical Medicine; and a booklet on rattlesnake bites folded up inside the medicine case, published ca. 1906. Additional items tested found in museum boxes labeled as having come from the Jack London estate included a Taylor thermometer certificate dated March 1906 along with the thermometer case; a vial of Chlorodyne (a mixture of morphine in chloroform and ethanol) from 1908; a vial of Formamint lozenge tablets (composed of formaldehyde and sucrose) from about 1914 and a Wyeth vial of opium tablets dated November 22, 1915. Only the outside glass surface of the vials with the unopened metal screw caps were tested for residues from the sweat or saliva left by fingers that may have touched the objects.

2.2. Chemicals and materials

Methanol (LC-MS Ultra CHROMASOLV, >99.9%), 2-propanol (LC-MS Ultra CHROMASOLV, >99.9%), acetic acid (eluent additive for LC-MS, >99.9), ammonium bicarbonate (AMBIC), formic acid, ammonium bicarbonate (AMBIC), trifluoroethanol (TFE) (>99%), ammonium hydroxide, and water (LC-MS Ultra CHROMASOLV, >99.9%) were purchased from Sigma-Aldrich (Milwaukee, USA). Microcon YM-5 and C₁₈ Zip-tip pipette tips were from Millipore UK Limited. The ultrapure water was obtained through a Millipore Milli-Q system (Milford, USA). The mixed-bed cation (SCX)/anion (SAX) exchange resins AG501 and C₈ and C₁₈ pearls were from Bio-Rad (Hercules, USA).

2.3. Synthesis and characterization of the EVA film

A special plastic-like film based on ethylene-vinyl acetate (EVA) as binder of ground AG 501 mixed-bed cation/anion exchange, C₈ and C₁₈ resins (all from Bio Rad) was prepared. A mixture was made comprising 70% 1–10 μm size ground beads and 30% EVA (the melting temperature was 75 °C). The proportion of the various resins in the plastic film was: 35% strong cation, 35% strong anion exchangers, 15% C₈ and 15% C₁₈ hydrophobic resins. The blend of melted EVA and Bio-Rad resins was poured in a “Brabender” mixer W30 and laminated via a “Brabender” extruder KE19 (both from Brabender GmbH, Duisburg, Germany) in the form of either a thin film or diskettes, having a thickness of 200 to 300 μm.

2.4. EVA film application

All items were in storage in the California Parks Service Barracks in Sonoma, CA. A total of 16 EVA samples were taken on 9 different objects. All films were immersed in 2.0 mL of doubly distilled water (18 M𝛺) for 10 min. Excess water was removed from each film by touching the edges of the films with a circle of Whatman No. 1 filter paper. The EVA diskettes were then immediately placed on the object, covered with a piece of Parafilm M followed by a round glass weight (200 g). Incubation was for 60 min at room temperature. The films were removed from the objects and placed into a small clear acrylic vial with a screw cap. Each vial was labelled on the cap with a black magic marker and a label with the number was fixed to the bottom of the vial. All 9 museum objects investigated were photographed before application of the films and then with the films applied and before the addition of the Parafilm M and the glass weight. The EVA films were only handled with sterilized plastic tweezers. One 65 mm × 10 mm EVA film was cut into smaller pieces for use with objects as required. For elution of material harvested by the EVA diskettes we used a two-step procedure: 70% methanol in doubly distilled water and a 60 mM ammonium acetate solution. The first step was collection of dry residues after elution in 70% methanol. The second step was an additional elution in 60 mM ammonium acetate.

2.5. GC-MS analysis

The two separate eluates were finally used for derivatization at 80 °C for 5 min in a mixed solvent of propionic anhydride and pyridine (5:2). The dried residues were reconstituted in 45 μL of propionic anhydride and 20 μL of pyridine. All reagents were vortex-mixed, then heated for 5 min at 80 °C and dried in air stream at 60 °C. The dried powders were reconstituted in 40 μL of methanol. For sample analyses a volume of 1 μL of each solution was injected into the GC-MS instrument. Gas chromatography–time of flight mass spectrometry (GC-TOF/MS) was run in a HP 6890 series GC, Split-less injector; 6890 series MS selective  detector (EI mode 70 eV HP). Column length 50 m; 5% phenyl methyl siloxane capillary column HP-5MS (id 0.25 mm). Morphine-d3 was used as internal standard. GC-MS was run with a linear temperature program from 30 °C to 280 °C. A fused-silica capillary column and helium as the carrier and makeup gas were used. The period of separation was ∼16 min. MS parameters: electron impact ionization source temperature (EI, 70 eV) was set at 250 °C; scan range 40/630 m/z, with an extraction frequency of 30 kHz. The chromatograms were acquired in TIC (total ion current) mode. Mass spectral assignment was performed by matching with NIST MS Search 2.2. Libraries, implemented with the MoNa Fiehns Libraries.

3.1. The artifacts tested

Table 1 lists the 9 items tested with the EVA technology along with their dates. We offer here some examples of these objects probed via EVA films. Figure 1 shows the A&F sole leather medicine case lid with two EVA diskettes applied. The left-hand cover of the case where fingers undo the snap; the lower right side of the typed instructions glued to the inside of the case; and an area on the outside of the leather case which appeared worn from holding the case in order to open the cover were all tested. Each diskette was covered with a piece of Parafilm M to prevent evaporation and then held down in place with a glass weight. A glass vial of opium tablets with a metal screw cap found in the A&F case was also tested. The 12-page booklet, Rattlesnake Bite and How to Cure It published about 1906 by Jack London’s friend George Wharton James was found folded up inside the case [9]. Jack London wrote that he wanted this booklet to go with him on his four-horse trip to Oregon from June to September 1911 [10, 11]. The cover of the booklet where fingers are used for opening was tested. Figure 2 shows the article by Breakstone on the surgical repair of ingrown toenails that was torn from the September 1911 issue of the American Journal of Clinical Medicine [12]. A possible dried blood stain on the left side of the first page was tested with an EVA film. Yoshimatsu Nakata, Jack London’s valet from 1908 to August 1915 claimed that Jack London, “had no corns but suffered quite a good deal from ingrowing [sic] toenails” [13].

Additional items tested included a certificate of analysis for a Taylor thermometer dated March 30, 1906. Jack London wrote while he was in the Solomon Islands battling malaria among the crew of the Snark that “It was the first time I had used my medicine-chest thermometer, and I quickly discovered that it was worthless” [14]. Figure 3 shows the two EVA disks on the Taylor certificate before the Parafilm M and glass weights were applied. The Taylor thermometer case was also tested. A vial of Chlorodyne, which is morphine, dissolved in a mixture of ethanol and chloroform was tested. The vial label showed that it came from a pharmacy in Suva, Fiji where Jack London and the crew of the Snark had arrived on their South Pacific voyage in May 1908 [15]. Figure 4 shows an empty vial of Formamint tablets. These are throat lozenges composed of formaldehyde and sucrose. A possible dried blood residue on the vial was tested. An ad for Formamint tablets in a San Francisco newspaper on February 8, 1914, included a testimonial from Jack London, “I am tremendously pleased with the antiseptic qualities of your Formamint Tablets. Formamint is a real cleaner of mouth germs” [16]. Finally, a bottle of opium tablets from Wyeth Pharmaceuticals provided by Bowman Pharmacy in Oakland, CA dated November 22, 1915 is shown in Figure 5. The left panel shows the applied EVA disc on its outside, whereas the right panel displays the same vial with the EVA disc wrapped up with Parafilm to prevent humidity loss during the 60 min application time. Letters from Bowman Pharmacy to Jack London in October 1915 informed him that they could not honour his request for additional opium tablets without a prescription [17]. They reminded him that this was due to the new Harrison Narcotics Act that began to be enforced in March 1915. This Federal law converted opium, morphine, codeine and heroin from over-the-counter drugs to prescription only. Jack London’s daughter Joan London, his oldest child, recounted the difficulty that this caused her father in obtaining his requested tablets of opium [18].

3.2. The drugs discovered

Table 2 is a list of the 12 different drugs recovered from the probed items. No opioids were recovered from the leather of the A&F medicine case, or the surface of a glass vial of opium tablets found in the case. Eight of the nine items examined were also found to contain quinine base or quinine hydrochloride, and various combinations of the Belladonna constituent’s atropine, hyoscyamine or scopolamine. Figure 7 displays the GC-MS profile of atropine and morphine (the other major peaks could not be identified exactly because the spectra were noisy) while Figures 8A and B give their respective MS spectra.

The drug N-(4-ethoxyphenyl) acetamide (Phenacetin) and phenyl salicylic acid (Salol) were found on 6 of the 9 objects. Phenacetin in the late 1940s was discovered to be converted in the body to acetaminophen, the actual active ingredient [19]. McNeill Laboratories (Johnson & Johnson) replaced Phenacetin with acetaminophen in 1955 and released it as Tylenol^®. Salol was the trademark name for phenyl salicylic acid and sold as an alternative to acetyl salicylic acid, the chemical name for aspirin. Quinine was found on 7 of the 9 objects. Tablets of 300 mg or more were used for malaria. Jack and his wife Charmian along with Nakata returned from the Snark voyage in 1909 infected with malaria. Lower doses of quinine at 14 mg per tablet were added to a wide variety of combination drugs where it was believed to act as a mild antipyretic. Eight of the 9 objects contained one or up to three of the different components of Belladonna namely atropine (d,l-hyoscyamine), l-hyoscyamine, and/or scopolamine (hyoscine). Compound drugs often contained one or more of these drugs where they were used to dry up mucous membranes.

Seven of the nine objects had traces, on their surface, of diacetylmorphine (heroin) and terpin hydrate (Table 3). The three major metabolites of diacetylmorphine, 6-acetylmorphine (6-AM), 3-acetylmorphine (3-AM) and morphine were also recovered from 5 of the 7 objects that tested positive for diacetylmorphine and terpin hydrate (Table 3). The combination terpin hydrate-heroin was a common over-the-counter drug used to treat a wide range of respiratory disorders. Terpin hydrate was the expectorant and diacetylmorphine acted as the cough suppressant. This drug was used for coughs, colds and the flu. Diacetylmorphine was replaced with codeine in 1924 and terpin hydrate with guaifenesin in the 1990s. Today this combination drug of guaifenesin–codeine is sold as Robitussin AC^® and is FDA approved for use in anyone over the age of 6 years. Six of the 9 objects contained surface residues from which morphine and atropine were also recovered.

It is noted that the 12 drugs discovered on the objects tested with the EVA technology could be accounted for by four vials of tablets found in Jack London’s Squibb medicine case. This travel medicine case dates from 1909 and is the case on display in the Jack London Museum in Glen Ellen, CA. These drugs include Acetphenetidin [sic] and Salol, Squibb No. 11355-S-1 (acetophenetidin [Phenacetin] and phenyl salicylate); Rhinitis, Half Strength, Squibb No. 11300-S-1 (quinine and Belladonna); Terpin Hydrate & Heroin, Squibb No. 11500-S-1 (terpin hydrate & diacetylmorphine) (Figure 6). No vials of morphine-atropine were discovered in either the A&F or Squibb medicine cases. However, the Squibb case has a vial of Follicular Tonsillitis Squibb No. 10805-S-1 which contains a combination drug that includes morphine sulphate, atropine and salicylates.