Transcript Slide 1

Department of Chemistry
Hill Research Group
Ion Mobility Spectrometry
Fast Qualitative Determination of Over-the-Counter Drugs and Cosmetics
Roberto Fernandez-Maestre; Abu B. Kanu; Prabha Dwivedi; and Herbert H. Hill, Jr.
Department of Chemistry,Washington State University, PullmanWA 99164-4630, USA
Overview
Results
• Ion mobility spectrometry (IMS) was used to determine mobility
spectra’s of common over-the-counter drugs and cosmetics.
• The analysis was performed in a home-built µ-spray ionization IMS.
• Instrument conditions summary: µ-spray voltage 12,500 V; Ion drift
voltage 8,480 V; Pullman atmospheric pressure 691-697 Torr; drift gas
temperature, 189.5 0C; drift length 17.4 cm.
• Successful implementation of µ-spray ionization IMS technology may
lead to a simple and practical instrumentation that can be used for fast
qualitative determination of over-the-counter drugs and cosmetics.
Introduction
Stand alone IMS was first introduced in 1970. Over the last couple of
decades IMS has grown to become an important analytical separation
technique. IMS has been found to be easy to use, and temporarily fast –
it separates ions in the millisecond time-scale, compared to techniques
like gas chromatography, liquid chromatography and capillary
electrophoresis that separates compounds in the minutes time-scale. IMS
is mechanically robust and very sensitive to a wide range of applications
(explosive residue detection, illicit drug residue detection, chemical
warfare agent detection, environmental monitoring, biological elucidation,
industrial process control, space shuttle cabin monitoring, and workplace
monitoring). The success of most of these applications was due to the
development of high-resolution IMS mass spectrometry with resolving
powers exceeding that of liquid chromatography and rivaling those of gas
chromatography. The goal of this research was to develop a stand alone
IMS that can be used for fast qualitative and quantitative determinations
of a wide class of chemical compounds. This work describes the
application of µ-spray IMS to the qualitative determination of over-thecounter drugs and cosmetics.
Table 1: Summary of instrumental condition for the home
Experimental
Sample preparation: Solid
samples were ground into
powder and dissolved in water.
Oils, colognes, and creams
were dissolved in methanol.
All
solutions
were
then
prepared to achieve a µ-spray
solvent composition of 49.5%
methanol, 49.5% water, and
1% acetic acid. Analysis were
performed in the positive ion
mode IMS.
Procedure: Mixtures of overthe-counter
drugs
and
cosmetics were sprayed into
the IMS to determine their
mobility spectra. Table 1 is a
summary of the instrumental
conditions
used
in
this
investigation.
built µ-spray IMS instrument.
Parameter
Reduced
mobility
L2 273.15 P
K0 


Vt d
T
760
Figure 1: Photograph of the home built µ-spray
IMS instrument.
5.4
cm
Drift tube length
17.4
cm
ESI voltage
12500
V
Voltage at front of tube
9500
V
Gate voltage
8480
V
Potential closing gate
±50
V
Aperture (last ring) voltage
205
V
Drift tube pressure
694 ± 3
Torr
Drift gas temperature
189.5
0C
ESI flow
1
µl min-1
Drift flow
1000
ml min-1
Gas
nitrogen
IMS gate pulse frequency
40
Hz
IMS scan time
35
ms
IMS gate pulse width
150
µs
over-the-counter
component
Active Ingredients
Reduced mobility (cm2 V-1
s-1)
µ-spray solvent
methanol, water, acetic acid
2.56; 2.01; 1.68
Ibuprofen
ibuprofen
2.04; 1.93; 1.69; 1.55; 1.47; 1.38; 1.22
Tylenol extra strength
acetaminophen
1.40
Tylenol PM
acetaminophen, diphenhydramine
1.40; 1.15
Hydrocodone
hydrocodone bitartate, acetaminophen
1.92; 1.73; 1.55; 1.30; 1.09
Nyquil night time
acetaminophen, pseudoephedrine HCl etc.
1.14; 1.01; 0.94; 0.88; 0.82; 0.78; 0.74
Fish oil
fish oil concentrate, gelatin, glycerin
0.97
Cephalexin antibiotic
cephalexin
1.10
Sulphameth/trimeth antibiotic
sulphamethoxazole, trimethoprim
2.38; 2.03; 1.76; 1.69; 1.56; 1.10
Echinacea Herb
echinacea engustifoia, echinacea pallida
1.95; 1.74; 1.37; 1.09
Mega men sport
vitamins A, C, E, D, K, B-6, B-12, thiamin
etc.
1.70; 1.51; 1.28; 1.16; 1.01
Jovan musk cologne
SD alcohol 39-C, fragrance, benzophenone2
1.32; 1.13
Lavender cologne
Fragrance, lavender oil, rosewood oil etc.
1.32
Vitamin E
d-alpha tocopheryl acetate, soybean oil etc.
0.74
Conclusions
• This work demonstrated that µ-spray IMS may be a viable alternative
for the fast qualitative determination of over-the-counter drugs and
cosmetics.
Figure 2: IMS spectra of µ-spray solvent and
pain/fever relievers. Reduced mobilities (cm2 V-1 s-1)
of the major peaks are shown on the spectra.
Figure 3: IMS spectra of hydrocodone pain reliever,
nyquil cold/flu syrup and antibiotics. Reduced
mobilities (cm2 V-1 s-1) of the major peaks are shown
on the spectra.
Settings
Reaction region length
Table 2: Summary of active ingredients and reduced mobilities for over-the-counter drugs and cosmetics.
Ion mobility fundamentals.
• Analysis time excluding sample preparation was in the milliseconds
time scale.
• Combination of a fast detection and low cost technique specific to IMS
instrumentation makes this approach an attractive alternative to
techniques like liquid chromatography for the determination of overthe-counter drugs and cosmetics.
• Identification of active ingredients responsible for the major reduced
mobility peaks in each spectra.
Further Work
• Use active ingredients standards to calibrate
concentrations of major reduced mobility peaks.
and
determine
References



Figure 4: IMS spectra of vitamins and pepto-bismol
syrup. Reduced mobilities (cm2 V-1 s-1) of the major
peaks are shown on the spectra.
Figure 5: IMS spectra of echinacea herb for cold/flu
remedy, jovan musk cologne and lavender cologne.
Reduced mobilities (cm2 V-1 s-1) of the major peaks are
shown on the spectra.

Cohen, M.J.; Karasek, F.W.; J. Chromatogr. Sci., 8: 1970; 330.
Eiceman, G.A.; Karpas, Z.; Ion Mobility Spectrometry, 2nd Ed., CRC
Press, Boca Raton, FL, 2005.
Whitehouse, C.M.; Dreyer, R.N.; Yamashita, M.; Fenn, J.B.; Anal. Chem.,
57(3): 1985; 675.
Fenn, J.B.; Man, M.; Meng, C.K.; Wong, S.F.; Whitehouse, C.M.; Science,
246: 1989; 64.
Acknowledgements
The work was supported partially by the EPA (Grant Number, X-970311010).