Nonaqueous capillary electrophoresis–mass spectrometry: A versatile, straightforward tool for the analysis of alkaloids from psychoactive plant extracts

Abstract

In this study we show that a nonaqueous capillary electrophoresis mass spectrometry (NACE-MS) method carefully optimized by a design of experiment can be applied to a very large number of alkaloids in different plant extracts. It is possible to characterize the pattern of the psychoactive alkaloids in several plant samples and preparations thereof, each presenting different challenges in their analysis. The method is shown to be able to separate structurally closely related substances, diastereomers and further isobaric compounds, to separate members of different alkaloid classes within one run and to tolerate significant matrix load. A comparison with methods presented in the literature reveals that a near-generic NACE-MS method for the fast profiling of alkaloids in forensically relevant plant samples has been developed.

Fast determination of harmala alkaloids in edible algae by capillary electrophoresis mass spectrometry

“…LODs ranged from 5.9 ng mL −1 for harmol to 1.2 ng mL −1 for harmine, harmane, and norharmane. Although most available reports are focused on method development and optimization [23][24][25], the only work reporting LODs for these alkaloids is that of Posch et al [27], who obtained LODs of 4.2 ng mL −1 for norharmane and 13.7 ng mL −1 for harmane using CE-MS, whereas in this work we obtained LODs of 1.2 ng mL −1 for both these analytes. An additional work analyzing these HAlks is that of Huhn et al [26], who used CE-LIF-MS; despite LODs not being calculated, their electropherograms revealed detectability of HAlks in solutions of 40 nmol L −1 .…”

“…A BGE with 50 mmol L −1 Tris (pH 7.8) was used, and addition of 20 % (v/v) methanol resulted in improved peak shape, peak capacity, and separation resolution. However, these BGE do not have the volatility necessary to generate an efficient electrospray in MS detection, to enable optimum sensitivity and signal stability and avoid the formation of salt deposits in the interface or at the entrance of the mass spectrometer [26,27,33,34]. Acidic BGEs containing acetic acid, formic acid, and moderate amounts of ammonia are usually preferred for CE-MS in positive-ion mode.…”

“…High-performance liquid chromatography (HPLC) with fluorescence or massspectrometry detection has usually been the technique of choice for determination of some HAlks in a variety of samples, including plant extracts, food, beverages, and biological fluids [5-7, 9, 11, 19-22]. Capillary electrophoresis (CE) has also been used [23][24][25][26][27], because HAlks present at least one amino ionizable group [16][17][18], but to a lesser extent despite the well-known advantages of CE [28]. Few works have revealed the potential of CE, and only for the qualitative analysis of standard mixtures or plant extracts with well-known high levels of HAlks.…”

“…Only a few authors have optimized methods for the separation of standard mixtures of HAlks using micellar electrokinetic chromatography (MEKC) with ultraviolet or laser-induced-fluorescence detection and capillary electrophoresis mass spectrometry (CE-MS), with limited success [23][24][25]. More recently, C. Huhn et al detected HAlks of Ayahuasca and different plant extracts (B. caapi and P. harmala) by capillary electrophoresis laser-inducedfluorescence mass spectrometry (CE-LIF-MS) and CE-MS with aqueous and nonaqueous background electrolytes (BGEs), without achieving full separation of some extracts [26,27].…”

A rapid and simple method for the determination of psychoactive alkaloids by CE‐UV: application to Peganum Harmala seed infusions

“…[11,19,22,[24][25][26][27] The resolution of the critical pair (3-4, Figure 3C, harmine-harmol) was complete (R s = 1.5) and between the rest of the pairs the R s was higher than 2.5. [11,19,22,[24][25][26][27] The resolution of the critical pair (3-4, Figure 3C, harmine-harmol) was complete (R s = 1.5) and between the rest of the pairs the R s was higher than 2.5.…”