PMID- 12850416
OWN - NLM
STAT- MEDLINE
DCOM- 20031009
LR  - 20190901
IS  - 0379-0738 (Print)
IS  - 0379-0738 (Linking)
VI  - 134
IP  - 2-3
DP  - 2003 Jul 8
TI  - Analysis of ecstasy tablets: comparison of reflectance and transmittance near 
      infrared spectroscopy.
PG  - 187-95
AB  - Calibration models for the quantitation of commonly used ecstasy substances have 
      been developed using near infrared spectroscopy (NIR) in diffuse reflectance and 
      in transmission mode by applying seized ecstasy tablets for model building and 
      validation. The samples contained amphetamine, 
      N-methyl-3,4-methylenedioxy-amphetamine (MDMA) and 
      N-ethyl-3,4-methylenedioxy-amphetamine (MDE) in different concentrations. All 
      tablets were analyzed using high performance liquid chromatography (HPLC) with 
      diode array detection as reference method. We evaluated the performance of each 
      NIR measurement method with regard to its ability to predict the content of each 
      tablet with a low root mean square error of prediction (RMSEP). Best calibration 
      models could be generated by using NIR measurement in transmittance mode with 
      wavelength selection and 1/x-transformation of the raw data. The models build in 
      reflectance mode showed higher RMSEPs using as data pretreatment, wavelength 
      selection, 1/x-transformation and a second order Savitzky-Golay derivative with 
      five point smoothing was applied to obtain the best models. To estimate the 
      influence of inhomogeneities in the illegal tablets, a calibration of the 
      destroyed, i.e. triturated samples was build and compared to the corresponding 
      data of the whole tablets. The calibrations using these homogenized tablets 
      showed lower RMSEPs. We can conclude that NIR analysis of ecstasy tablets in 
      transmission mode is more suitable than measurement in diffuse reflectance to 
      obtain quantification models for their active ingredients with regard to low 
      errors of prediction. Inhomogeneities in the samples are equalized when measuring 
      the tablets as powdered samples.
FAU - Schneider, Ralph Carsten
AU  - Schneider RC
AD  - Department of Pharmaceutical Analysis, Pharmaceutical Institute, University of 
      Tubingen, Auf der Morgenstelle 8, 72076 Tubingen, Germany.
FAU - Kovar, Karl-Artur
AU  - Kovar KA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Ireland
TA  - Forensic Sci Int
JT  - Forensic science international
JID - 7902034
RN  - 0 (Amphetamines)
RN  - 0 (Central Nervous System Stimulants)
RN  - 0 (Hallucinogens)
RN  - 0 (Tablets)
RN  - KE1SEN21RM (N-Methyl-3,4-methylenedioxyamphetamine)
SB  - IM
MH  - Amphetamines/analysis
MH  - Calibration
MH  - Central Nervous System Stimulants/analysis
MH  - Chromatography, High Pressure Liquid
MH  - Forensic Medicine/methods
MH  - Hallucinogens/*analysis
MH  - Molecular Structure
MH  - N-Methyl-3,4-methylenedioxyamphetamine/*analysis
MH  - Reproducibility of Results
MH  - Spectroscopy, Near-Infrared/*methods
MH  - Tablets/*chemistry
EDAT- 2003/07/10 05:00
MHDA- 2003/10/10 05:00
CRDT- 2003/07/10 05:00
PHST- 2003/07/10 05:00 [pubmed]
PHST- 2003/10/10 05:00 [medline]
PHST- 2003/07/10 05:00 [entrez]
AID - S0379073803001257 [pii]
AID - 10.1016/s0379-0738(03)00125-7 [doi]
PST - ppublish
SO  - Forensic Sci Int. 2003 Jul 8;134(2-3):187-95. doi: 10.1016/s0379-0738(03)00125-7.