Technological challenges in the development and testing of illicit narcotics include assuring safety of researchers and operations personnel from drug exposure, assessing the efficiency of sampling and sample handling, checking for artifacts introduced by field procedures, and maintaining quality control/quality assurance. The dye methylene blue was chosen as a simulant for cocaine HCl and heroin HCl. The similarities include the presence of fused ring systems, molecular weights over 300 g/mol, and melting points between 200 and 300 degrees C. A significant difference is that methylene blue has a much lower solubility in water than cocaine HCl and heroin HCl. Experiments have been conducted to successfully increase the solubility of the simulant to match those of cocaine HCl and heroin HCl by adding solidum methyl sulfate.

We report the use of solid phase microextraction (SPME) combined with ion mobility spectrometry (IMS) for sampling, screening and identification of organic compounds that are readily detected by IMS. This is a new SPME application. SPME has emerged recently as an excellent sample preparation technique for gas chromatography (GC) and high performance liquid chromatography (HPLC). We have found that SPME can be used very conveniently with IMS. An example of SPME-IMS is described using SPME headspace sampling at room temperature with 0.1 mt vials containing 1.0 microgram or less of either cocaine freebase or cocaine hydrochloride. This is followed by analysis using IMS. A hole, drilled in the IMS sample ticket holder, serves as the SPME-IMS interface.

Achieving efficiency in sampling, and sample handling of contraband drugs is integral to the successful operation of field detection and analytical systems, and represents a major technology challenge. One of the most popular methods of sampling surfaces for contraband drugs is the use of swipes (e.g., various filter papers and cloths). However, the detailed evaluation of swiping procedures, swipe materials, the effect of surfaces (composition, porosity, roughness, etc.), wet swipes vs. dry swipes, environmental factors (humidity, temperature, aging, etc.), to mention several; have not been performed. We have initiated studies of sampling and sample handling as an adjunct to the development of man-portable detection instrumentation for contraband drugs. The goal is to understand the parameters critical to achieving maximum efficiency in sampling surfaces. The choice of swipe material makes a great difference. The nature of the surface sampled is very important as well. Our studies have shown that various degrees of roughness, porosity, and mechanical damage can contribute to as much as 32% of the target drug being retained by the surface after swiping. This paper will present details of our progress in understanding the various parameters in sampling with a goal to assist in standardizing field sampling as much as possible among detection instruments.

Solid phase microextraction (SPME) has emerged as a rapid alternative to conventional sample extraction techniques. SPME can be used in solids, liquids, and sample headspace. Compounds are sorbed by a stationary phase coated on a fused silica fiber. The compounds are desorbed, and analyzed using gas chromatography (GC), and high performance liquid chromatography (HPLC). As a part of the present work we have found that SPME can also be used conveniently with ion mobility spectrometry (IMS). Cocaine and heroin vapors sorbed on a SPME fiber were detected using IMS. The use of SPME-GC or SPME-HPLC has been reported in analysis of urine samples containing cocaine and its metabolites. We are evaluating SPME-IMS, and SPME-GC systems for the detection of cocaine and heroin and their decomposition products in the headspace above surfaces. This is part of our research on the surface decomposition of contraband drugs for detection applications. This paper will give a variety of examples in the use of SPME in the detection of contraband drugs and their reaction/decomposition products in the vapor state. An example is the detection of cocaine in the headspace above cocaine HCl at room temperature.

The surface chemistry of contraband drugs is very important in many detection techniques. It is also important in choosing materials for sampling and sample handling. The chemical nature of surfaces may facilitate drug decomposition or serve to stabilize the drugs. We have developed a simple technique to study the chemistry of contraband drugs such as cocaine HCl at nanogram levels. The normal operating modes of an IONSCAN 400 ion mobility spectrometer were adjusted to allow the chemistry of the drugs to be examined in the sample chamber of the spectrometer. For example, a membrane with deposited drug is held in the sample chamber at a specified temperature up to 20 seconds with no air flow. An ON-OFF valve was placed in- line just before the carrier gas enters the desorption chamber where samples are heated. This modification allows the gas flow to be manually turned off while the sample is being heated. We have used this technique to examine the pyrolysis of cocaine hydrochloride under a variety of conditions. At the end of the designated reaction time, the air flow is turned on allowing the reaction products and any starting materials to flow into the spectrometer for analysis. This technique has allowed studies of the stability of the drugs at various temperatures on different surfaces. For example, evidence was obtained of cocaine HCl decomposition at 75 degrees for 5 seconds using Teflon as the support material. The use of this technique has also assisted us in choosing materials for pyrolysis studies in which the goal is the decompose target drugs quickly and efficiently for detection applications.

The potential use of plasma-deposition techniques for the preparation of recognition coatings for mass sensors was investigated. Ethylenediamine and 4-vinylpyridine plasma-produced coatings and solution-deposited coatings from commercially available polyethyleneimine and poly(4-vinylpyridine) on quartz crystal microbalances (QCMs) were examined for the detection of acetic acid and other vapors. Freshly prepared QCM plasma-deposited recognition coatings from both ethylenediamine and 4-vinylpyridine were found to be very sensitive to acetic acid vapors. However the sensitivity decreased rapidly with time. Aging effects with solution deposited polymers films were noted as well. It was concluded that plasma-deposition of recognition coatings has great potential in the preparation of recognition coatings. In addition to well known advantages of the use of plasmas for surface film preparation or modification, the technique offers a one-step process of synthesizing and depositing high molecular weight films from volatile compounds not polymerizable by conventional means. A major disadvantage is that the chemical nature of the resulting coating is not easily predictable. However, careful choice of carrier gas and recognition film precursor can do much to simplify the design of effective recognition coatings.

The U.S. Environmental Protection Agency (EPA) has been examining the potential of combining sonication with available measurement technologies for monitoring chlorinated hydrocarbons in water. The chloride ion (Cl-) concentration, conductivity, and pH were measured before and after sonication. Cl- could be detected in aqueous solutions of 3-80 ppm carbon tetrachloride (CCl4), chloroform (CHCl3), and trichloroethylene (TCE) after 1 min of sonication. The increases of Cl- were accompanied by increases in conductivity and decreases in pH. The conductivity changes were higher than expected based on measured Cl-. Ion chromatography of solutions before and after sonication showed that formate ion (HCOO-) was also formed. Other ions may have formed as well, but the concentrations were too low to allow their detection relative to HCOO- and Cl-. The results achieved serve as proof-of-principle and form a base of information which can be used to develop ultrasound monitoring methods for these compounds. Aromatic and polyaromatic chloro compounds represented by chlorobenzene (Ph-Cl) and polychlorobiphenyls (PCBs), respectively, did not release Cl- upon sonication as readily as did CCl4, CHCl3, and TCE. The PCB solutions gave no measurable changes in either Cl-, conductivity, or pH under the conditions of the experiments described.

The recent analytical literature on the application of luminescence techniques to the measurement of various classes of environmentally significant chemicals has been reviewed. Luminescent spectroscopy based methods are compared to other current techniques. Also, examples of recently developed applications of luminescence to environmental monitoring are provided. The advantages and disadvantages of luminescence measurements for field screening measurements are discussed.

Research results are described that address the sorption of several polyaromatic hydrocarbons (PAHs) on solid phase extraction membranes as a function of concentration for a selected time period, followed by front-surface ultraviolet-visible fluorescence spectroscopy for detection. Results indicate a linear response for a range of concentrations, which suggests the potential for quantitative analysis of individual PAHs. Subsequent experiments to examine more complex PAH mixtures, ie petroleum oils, as detected by fluorescence emission following sorption on the membranes and to analyze simple PAH mixtures by synchronous fluorescence indicated greater difficulty in analysis for mixtures as compared to analysis for individual PAHs. Possible strategies are presented for improving the usefulness of front surface luminescence as an analytical technique for PAHs sorbed on solid phase extraction membranes and related materials that have favorable sorption properties for PAHs. The combined technique of solid phase extraction and solid state luminescence continues to show merit for field and laboratory screening methods if certain problems can be solved.

Semivolatile organic compounds in water can be determined by using field-compatible methods through extraction with alkyl-bonded membranes, vaporization by thermal desorption, and characterization by ion mobility spectrometry (IMS). Water containing phthalate esters at 1-50 ppm was extracted for 1 h as an unstirred solution by direct contact with thin strips of C8-bonded membranes. Vapors released from the strips at 200-degrees-C were analyzed with a hand-held ion mobility spectrometer (IMS). Ion mobility spectra for phthalate esters were comprised of a single intense negatively charged product ion and peaks were well-resolved in spectra for mixtures of four dialkyl phthalates. Mixtures of these phthalate esters showed composite spectra formed through competitive ionizations. Response for a hand-held ion mobility spectrometer was proportional to aqueous concentrations of dimethyl phthalate from 1-50 ppm and detection limits were ca. 0.5 ppm for a 60-min extraction. A solution of 50 ppm of dimethyl phthalate in water saturated with kerosine was used to illustrate potential applications with chemically complex samples.

Research results are described which bring out the potential of using commercially available solid-phase extraction membranes and solid-state spectroscopy for monitoring water pollution. The membranes are used to preconcentrate pollutants by sorption from aqueous solution followed by nondestructive spectroscopic measurements. Solid-state fluorescence measurements using Empore(TM) C18 membranes were employed in the laboratory for concept validation studies. Tabs from the membranes were suspended in solutions containing parts per billion (ppb) concentrations of anthracene for specific periods of time. The tabs were withdrawn, allowed to dry briefly in air, and then examined for-fluorescence. The potential exists for at least semiquantitative analysis. The method is relatively simple. Use of extraction membranes in a dip-stick mode is new, as is the use of the membranes with solid-state fluorescence spectroscopy. Limitations are being defined.

ChemInformVolume 18, Issue 51 Physical Organic Chemistry ChemInform Abstract: peri-Interaction: Crystal Structure of 1,8-Bis-(methylene-4,4′-bipyridinium)-naphthalene S. MUNAVALLI, S. MUNAVALLI US Army Chem. Res., Dev. Eng. Cent., Res. Dir., Aberdeen Proving Ground, MD 21010-5423, USASearch for more papers by this authorE. J. POZIOMEK, E. J. POZIOMEK US Army Chem. Res., Dev. Eng. Cent., Res. Dir., Aberdeen Proving Ground, MD 21010-5423, USASearch for more papers by this authorC. S. DAY, C. S. DAY US Army Chem. Res., Dev. Eng. Cent., Res. Dir., Aberdeen Proving Ground, MD 21010-5423, USASearch for more papers by this author S. MUNAVALLI, S. MUNAVALLI US Army Chem. Res., Dev. Eng. Cent., Res. Dir., Aberdeen Proving Ground, MD 21010-5423, USASearch for more papers by this authorE. J. POZIOMEK, E. J. POZIOMEK US Army Chem. Res., Dev. Eng. Cent., Res. Dir., Aberdeen Proving Ground, MD 21010-5423, USASearch for more papers by this authorC. S. DAY, C. S. DAY US Army Chem. Res., Dev. Eng. Cent., Res. Dir., Aberdeen Proving Ground, MD 21010-5423, USASearch for more papers by this author First published: December 22, 1987 https://doi.org/10.1002/chin.198751055Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume18, Issue51December 22, 1987 RelatedInformation

i o n and the scope of the synthesis have been f u r t h e r explored.The s u g g e s t i ~n l , ~ t h a t t h e coupling o f the azapyridocyanine moiety t o a conjugated polymeric backbone might y i e l d superconducting polymers has generated considerable i n t e r e s t 3 -6 i n the synthesis of t h i s novel group of heterocycles.

Carbon-13 NMR spectroscopy, employing high power decoupling and magic angle spinning, has been used to determine the availability of amine functionality of 4-vinylpyridine on charcoal for quaternization with 13C enriched methyl iodide. The quaternary salt is formed as shown by its chemical shift of 45 ppm; the source of the 23 ppm linewidth is not clear. The cross-polarization rate implies a very rigid structure for the amine salt, which is consistent only with polymerization of the 4-vinylpyridine on the surface. The axial powder pattern for the bare charcoal shows it to be almost completely aromatic with carbon atoms at sites of three-fold symmetry.