Atmospheric Solid Analysis Probe-Mass Spectrometry (ASAP-MS) for rapid screening of drugs of abuse in biological fluidsCamilla Liscio, Bryan McCullough, Christopher HopleyQueens Road, Teddington, Middlesex, TW11 0LY, UKCamilla.Liscio@lgcgroup.com

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IntroductionScreening of drugs of abuse and their metabolites in biological matrices is a frequent practice in a variety of scenarios. Performing on-site screening for abused drugs could provide immediate scientific evidence and improve the quality of clinical management in emergencies. Direct analysis (DA) by ambient mass spectrometry (MS) permits rapid data acquisition (seconds per sample) bypassing time consuming and complex sample pre-treatment. Furthermore, a combination of this ambient desorption ionization technique with the emerging transportable mass-spectrometers could provide a straightforward and very powerful option for on-site analyses. This study investigated the performances of an Atmospheric Solid Analysis Probe-Mass Spectrometry (ASAP-MS) quantitative method for the detection of an array of abused drugs and metabolites in urine in view of a potential application for on-site analyses.

1) Glass capillary dipped in sample

2) Capillary mounted in holder

3) Sample desorbed and ionised by Corona Discharge

Results & discussionThe initial ASAP work did not prove to be promising, however a minor modification to the technique, with the introduction of a disposable micro capillary, was found to offer a solution to the analysis. The position of the capillary in the source is determinant to obtain an efficient and homogenous spray of the solution. Changes in the solvent properties (i.e. boiling point and viscosity) can affect the spray as well and consequently influence reproducibility. Table 1 summarises the Signal/Noise ratios obtained for the tested analytes for the lowest concentration and the standard threshold levels for confirmatory tests by GC-MS, with the exception of benzoylecgonine and amphetamine, which could be detected at the top end of the range. Linearity was observed for all the detected compounds. Figure 2 shows the signal linearity for cocaine and MDMA as an example. Intra-day variability ranged between 20% and 30% depending on the compound.

Compound Concentration [ng/mL]

S/N (n=3)

GC-MS confirmation [ng/mL]

Cocaine 50 40 150

Ecgoninemethylester 50 44 150

MDMA 150 41 500

MDA 150 18 500

Table 1

Conclusions• No time consuming and complicated

sample preparation required

• 45 samples in one hour (approximately 1 minute analysis time plus few seconds to sample)

• Low sample volume required (i.e. 2 µL sample)

• Good sensitivity (e.g. S/N >>10 at concentrations 3 time lower than the cut-off levels of the confirmatory method)

• Good linearity in the tested concentration range

• Application of this technique coupled to transportable MS could lead to very promising outcomes for on-site drug screening (e.g. saliva)

Materials & methods• Instrumentation: Micromass Z-spray

source fitted with a corona discharge pin and a heated nebuliser Ion Sabre APCI customised for atmospheric solids analysis probe (ASAP) coupled to a Micromass Quattro Ultima QqQ MS [ APCI probe T=350°C, Desolvation gas flow = 250L/hr, Source Block T= 120 °C, Cone Gas (Nitrogen) = 90 L/hr, Corona Voltage=10 V Cone Voltage=25 V]

• Data Acquisition: Single Ion Monitoring (SIM)

• Matrix: Synthethic urine (Surine™ Negative Urine Control, Sigma, UK)

• Target analytes: Cocaine, Cocaine-D3 (IS), Benzoylecgonine, Ecgoninemethylester, Amphetamine, Amphetamine-D11 (IS), MDMA, MDMA-D5 (IS), MDA

• Concentration range: 50-500 ng/mL in MeOH for Cocaine, Benzoylecgonine and Ecgoninemethylester and 150-1500 ng/mL for Amphetamine, MDMA and MDA; IS concentration 150 ng/mL for Cocaine-D3 and 500 ng/mL for Amphetamine-D11 and MDMA-D5

• Sample Volume: 2 µL (disposable glass microcapillary pipette)

y = 0.0047x + 0.0929 R = 0.99444

0

0.5

1

1.5

2

2.5

3

3.5

0 100 200 300 400 500 600

IS r

atio

Concentration [ng/uL]

Cocaine in urine

y = 0.001x + 0.1877 R = 0.99378

0

0.5

1

1.5

2

2.5

0 200 400 600 800 1000 1200 1400

IS r

atio

Concentration [ng/uL]

MDMA in urine

Figure 1

Figure 2Capillary

Source Cone

Corona Discharge Pin

Acknowledgements:

The work described was supported by the UK National Measurement System Chemical and Biological Metrology Programme.

LGC ASAP-MS Technical Poster.indd 1 19/08/2014 09:11