Fast Qualitative Determination of Over-the-Counter Drugs and Fast Qualitative Determination of Over-the-Counter Drugs and CosmeticsCosmetics

Roberto Fernandez-Maestre; Abu B. Kanu; Prabha Dwivedi; and Herbert H. Hill, Jr.

Department of Chemistry, Washington State University, Pullman WA 99164-4630, USA

Conclusions

Introduction

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.

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-the-counter drugs and cosmetics. Experimental

Acknowledgements

Figure 1: Photograph of the home built µ-spray IMS instrument.

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.

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 over-the-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.

• This work demonstrated that µ-spray IMS may be a viable alternative for the fast qualitative determination of over-the-counter drugs and cosmetics.

• 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 over-the-counter drugs and cosmetics.

The work was supported partially by the EPA (Grant Number, X-97031101-0).

Further Work

References

Overview

• Identification of active ingredients responsible for the major reduced mobility peaks in each spectra.

• Use active ingredients standards to calibrate and determine concentrations of major reduced mobility peaks.

Parameter SettingsReaction region length 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

Table 1: Summary of instrumental condition for the home built µ-spray IMS instrument.

Table 2: Summary of active ingredients and reduced mobilities for over-the-counter drugs and cosmetics. over-the-counter

componentActive 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, benzophenone-2

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

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.

Ion mobility fundamentals.

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Reduced mobility

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.

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.

Department of Chemistry Hill Research Group

Ion Mobility Spectrometry