Detection of {sup 14}N and {sup 35}Cl in cocaine base and hydrochloride using NQR, NMR, and SQUID techniques

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Analytical Chemistry (Washington)

DOI:https://doi.org/10.1021/ac00109a053· OSTI ID:81357

Yesinowski, J P; Buess, M L; Garroway, A N ^[1]; Ziegeweid, M; Pines, A ^[2]

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1. Naval Research Lab., Washington, DC (United States)
2. Univ. of California, Berkeley, CA (United States)

Results from {sup 14}N pure NQR of cocaine in the free base form (cocaine base) yield a nuclear quadrupole coupling constant (NQCC) e{sup 2}Qq/h of 5.0229 ({+-}0.0001) MHz and an asymmetry parameter {eta} of 0.0395 ({+-}0.0001) at 295 K, with corresponding values of 5.0460 ({+-}0.0013) MHz and 0.0353 ({+-}0.0008) at 77 K. Both pure NQR (at 295-77 K) and a superconducting quantum interference device (SQUID) detector (at 4.2 K) were used to measure the very low (<1 MHz) {sup 14}N transition frequencies in cocaine hydrochloride; at 295 K the NQCC is 1.1780 ({+-}0.0014) MHz and the asymmetry parameter is 0.2632 ({+-}0.0034). Stepping the carrier frequency enables one to obtain a powder pattern without the severe intensity distortions that otherwise arise from finite pulse power. A powder pattern simulation using an NQCC value of 5.027 MHz and an asymmetry parameter {eta} of 0.2 agrees reasonably well with the experimental stepped-frequency spectrum. The use of pure NQR for providing nondestructive, quantitative, and highly specific detection of crystalline compounds is discussed, as are experimental strategies. 31 refs., 8 figs., 1 tab.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 81357
• Journal Information: Analytical Chemistry (Washington), Journal Name: Analytical Chemistry (Washington) Journal Issue: 13 Vol. 67; ISSN ANCHAM; ISSN 0003-2700
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
42 ENGINEERING
44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
66 PHYSICS
CHLORINE 35
COCAINE
DETECTION
NITROGEN 14
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEAR QUADRUPOLE RESONANCE
SQUID DEVICES
USES