LC/MS Analysis of Illicit Phenethylamine and Cathinone “Bath Salts” in Plasma on Ascentis® Express HILIC after Extraction using SPME LC Tips
Materials
analytical column
accessory
mobile phase component
standard
Butylone hydrochloride solution
1.0 mg/mL in methanol (as free base), ampule of 1 mL, certified reference material, Cerilliant®Buphedrone hydrochloride solution
1.0 mg/mL in methanol (as free base), ampule of 1 mL, certified reference material, Cerilliant®Ethylone hydrochloride
1.0 mg/mL in methanol (as free base), ampule of 1 mL, certified reference material, Cerilliant®4-Fluoromethcathinone hydrochloride solution
1.0 mg/mL in methanol (as free base), ampule of 1 mL, certified reference material, Cerilliant®3-Fluoromethcathinone hydrochloride solution
1.0 mg/mL in methanol (as free base), ampule of 1 mL, certified reference material, Cerilliant®Mephedrone hydrochloride solution
1.0 mg/mL in methanol (as free base), ampule of 1 mL, certified reference material, Cerilliant®Methylone hydrochloride
1.0 mg/mL in methanol (as free base), ampule of 1 mL, certified reference material, Cerilliant®Methedrone hydrochloride solution
1.0 mg/mL in methanol (as free base), ampule of 1 mL, certified reference material, Cerilliant®CONDITIONS
sample/matrix
Rat plasma was adjusted to pH 3.0 with phosphoric acid and spiked at 50 ng/mL with selected Bath Salt compounds. (A 750 μL aliquot of the spiked plasma was placed into each well of a 1.0 mL 96 well collection plate.)
SPME fiber
SPME LC tip, mixed-mode (57234-U)
extraction
SPME LC fibers were preconditioned in 50:50 methanol:water and placed into sample wells. Extraction was performed for 15 minutes on an IKA VORTEX MS3 shaker at 500 rpm.
desorption process
SPME LC Tip fibers were then desorbed in 100 μL of 0.5% ammonium hydroxide in methanol for 60 minutes at 500 rpm vortex.
desorption process
Desorbed samples were evaporated and reconstituted in 40 μL of acetonitrile and injected directly into the LC/MS system.
column
Ascentis Express HILIC, 10 cm x 2.1 mm I.D., 2.7 μm particles (53939-U)
mobile phase
5 mM ammonium formate (98:2 acetonitrile:water)
flow rate
0.6 mL/min
pressure
1842 psi (127 bar)
column temp.
35 °C
detector
ESI(+), 100-1000 m/z
injection
1 μL
Description
Analysis Note
Solid phase microextraction (SPME) was used in this application to extract phenethylamine and cathinone "bath salts" from spiked plasma. After elution from the SPME fiber, the compounds were separated on an Ascentis Express HILIC column and detected using MS ESI(+) detection. Ultra high purity LC-MS solvents were used to supply low background interference and low particulate contaminants for robust, trouble-free operation. Cerilliant CRMs provided reliable identification and quantification.
Legal Information
Ascentis is a registered trademark of Merck KGaA, Darmstadt, Germany