Identification of the polymer-bounded drugs on the fabric surface: A challenge to the forensic drug analysts.

Drug trafficking through concealment has always been a method of choice for drug traffickers all around the world. This case shares a new trend in the smuggling of illicit drugs by applying a coating of drug and polymer mixture on fabric. A white fabric sample was submitted by a law enforcement agency to detect the presence of any explosive material on its surface. Later on it was also tested for illicit drugs. Stereomicroscope and Scanning Electron Microscope/Energy Dispersive X-ray Detector (SEM/EDX) were applied for microscopic examination. Acetone extract of the sample was analyzed for explosives by explosive detection kit, Gas Chromatography Mass Spectrometry (GCMS), and Fourier Transform Infrared Spectroscopy (FTIR). The routine method involving methanol as solvent was used to check heroin presence. Methanol extract of the sample was analyzed by Mecke test and GCMS. Stereomicroscope and SEM/EDX revealed the presence of some unusual coating on one side of fabric. No explosive material was detected; instead GCMS (method 1) confirmed the presence of heroin (mass fragments 268, 310, 327, and 369 m/z) and FTIR spectrum revealed presence of a polymeric material (dyneema). No drug was identified by GCMS (method 2). Method 2 was modified by replacing methanol with acetone and including an additional step of sonication for 30 min. Acetone extract showed green color with Mecke reagent and a strong signal of heroin on GCMS. This modified extraction method acted well to unbind the coated material from the fabric and to disentangle the drug from the polymer.

Dimeric self-assembly of pyridyl guanidinium carboxylates in polar solvents.

A series of pyridyl guanidinium-carboxylates has been prepared and the dimeric self-assembly of these studied in H(2)O/DMSO mixtures, principally using dilution isothermal calorimetry. Compounds 5 and 6, incorporating an aromatic ring in the "tethering" region between the guanidinium and carboxylate groups, demonstrate the strongest dimerisation in neat DMSO. X-ray crystal structures of 5 and 6 reveal two different dimerisation architectures in the solid-state, but both involve carboxylate-guanidinium salt bridges as anticipated, and π-π interactions. Compounds 10-16 incorporating peptidic fragments between the guanidinium and carboxylate groups, showed reduced dimerisation strength with increased amino acid content, but also sustained dimerisation under increasingly aqueous conditions, up to 50% H(2)O/DMSO in the case of 14 and 15. The extent of our study in H(2)O/DMSO mixtures was determined by substrate solubility of 10-16, and not the limit of self-assembly.

Dimeric supramolecular motifs of two carboxylate-guanidinium compounds.

The structures of N-benzyl-N'-{6-[(4-carboxylatobenzyl)aminocarbonyl]-2-pyridylmethyl}guanidinium, C(23)H(23)N(5)O(3), (I), and N-[2-(benzylaminocarbonyl)ethyl]-N'-{6-[(4-carboxylatobenzyl)aminocarbonyl]-2-pyridylmethyl}guanidinium monohydrate, C(26)H(28)N(6)O(4).H(2)O, (II), both form three-dimensional supramolecular hydrogen-bonded networks based on a dimeric primary synthon involving carboxylate-guanidinium linkages. The differences in the geometries and hydrogen-bonding connectivities are driven by the additional methylpropionamide group and water of crystallization of (II).

1-(4-Hydr-oxy-2-methyl-1,1-dioxo-2H-1,2-benzothia-zin-3-yl)ethanone.

In the title compound, C(11)H(11)NO(4)S, the thia-zine ring adopts a distorted half-chair conformation. The enolic H atom is involved in an intra-molecular O-H⋯O hydrogen bond, forming a six-membered ring. Mol-ecules are linked through weak inter-molecular C-H⋯O hydrogen bonds, resulting in chains lying along the b axis.