Analyzing Synthetic Cathinones Using Direct Sample Analysis Time-of-Flight Mass Spectrometry

Jul 01, 2014

Direct sample analysis coupled to high-resolution time-of-flight mass spectrometry (TOF-MS) may be effective at analyzing synthetic cathinones, especially for qualitative analysis, because it does not require potentially tedious sample preparation. This technique will allow for a more rapid and simplistic analysis of synthetic drugs and increase laboratory throughput, as evidenced by the work of other researchers with different instrumentation for different compound classes.

Synthetic drugs known as "bath salts," "plant food," and "jewelry cleaner" have become prominent in the United States since their introduction in 2009 (1). Products exhibit colorful packaging labels that state "not for human consumption" to allow for legal possession and recreational use by circumventing control mechanisms (2). These drugs are sold extensively via online retailers and are also carried in "head shops" and independently owned convenience stores (3). The products generally contain cathinone derivatives and produce stimulant effects similar to methamphetamine and ecstasy (4). Cathinone is a schedule I drug under the Controlled Substances Act (CSA), but it has been modified to produce a wide variety of synthetic drugs. There are dozens of known cathinone derivatives on the market and hundreds more that are possible (5). In June of 2012 the United States Congress passed the Food and Drug Administration (FDA) Safety and Innovation Act that extended the CSA to include 3,4-methylenedioxypyrovalerone (MDPV) and 4-methylmethcathinone (mephedrone) as schedule I drugs (6).

Synthetic cathinones are sold as tablets, capsules, and powders and have been combined with other illicit controlled substances in previous cases (7). The abuse of these drugs has also led to deaths globally (8,9).

These products can be difficult to analyze because of the possible insolubility of adulterants, cutting agents, or other added materials. Generally, analysis requires some type of sample preparation to obtain the active compounds in a suitable form, such as an organic solvent solution. Direct sample analysis time-of-flight mass spectrometry (TOF-MS) may be effective, especially for qualitative analysis, because it does not require potentially tedious sample preparation. This technique allows for a more rapid and simplistic analysis of synthetic drugs and increases laboratory throughput, as evidenced by the work of other researchers with different instrumentation for different compound classes (10,11). Analysis of such designer drugs and the identification of individual compounds may help reduce their production and abuse.

Materials and Methods

Chemicals and Materials

Standard reference materials consisting of 3,4-methylenedioxypyrovalerone (MDPV), 4-methylmethcathinone (mephedrone, 4-MMC), 3,4-methylenedioxy-N-methylcathinone (methylone), butylone, naphyrone, 3-fluoromethcathinone (3-FMC), 4-methylethcathinone (4-MEC), α-pyrrolidinopentiophenone (α-PVP), 3',4'-methylenedioxy-α-pyrrolidinobutiophenone (MDPBP), 3-methyl-α-pyrrolidino-propiophenone (3-MPPP), ethcathinone, and (S)-2-diphenylmethylpyrrolidine ([S]-desoxy-D2PM) were obtained from Cayman Chemical Company. Methanol (high performance liquid chromatography [HPLC]-grade) was purchased from Avantor. All solvents and chemicals used in the experiment are of a minimum purity of ACS reagent grade.