A novel analytical approach combining solid-phase microextraction (SPME)/ gas chromatography ion trap mass spectrometry (GC-IT-MS) was developed for the detection and quantification N,N-dimethyltryptamine (DMT), a powerful psychoactive indole alkaloid present in a variety of South American indigenous beverages, such as ayahuasca and vinho da jurema. These particular plant products, often used within a religious context, are increasingly consumed throughout the world following an expansion of religious groups and the availability of plant material over the Internet and high street shops. The method described in the present study included the use of SPME in headspace mode combined GC-IT-MS and included the optimization of the SPME procedure using multivariate techniques. The method was performed with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber in headspace mode (70 min at 60 °C) which resulted in good precision (RSD<8.6%) and accuracy values (71–109%). Detection and quantification limits obtained for DMT were 0.78 and 9.5 mg L−1, respectively and good linearity (1.56–300 mg L−1, r2=0.9975) was also observed. In addition, the proposed method showed good robustness and allowed for the minimization of sample manipulation. Five jurema beverage samples were prepared in the laboratory in order to study the impact of temperature, pH and ethanol on the ability to extract DMT into solution. The developed method was then applied to the analysis of twelve real ayahuasca and vinho da jurema samples, obtained from Brazilian religious groups, which revealed DMT concentration levels between 0.10 and 1.81 g L−1.

pH 1 sounds rather excessive, lots of salts
I'd have gone pH 4 at the lowest, nLC-MS with a waters nano-acuity 100 uM i.d. C-18 column, 0.1% FA in H20 in res A, 0.1% FA in ACN in res B, 0 - 20% B for 20 mins, 100% B @ 30 - 40 mins, and 20% B at 45-50 mins. 30 uL/min flowrate, 5 kV electrospray.

They also fiddled with extraction parameters and show that 50/50 water:ethanol extracts very high amount of dmt at just room temperature, which is only marginally worse than using hydrochloric acid, pH=1 at 100 degrees Celsius (Table 3). The latter is an interesting lead for advancing extraction methodologies.

Layman summary:
The authors analysed both ayahuasca and vinho da jurema, and quantified dmt in it using admittedly fancy equipment. They also fiddled with extraction parameters and show that 50/50 water:ethanol extracts very high amount of dmt at just room temperature, which is only marginally worse than using hydrochloric acid, pH=1 at 100 degrees Celsius (Table 3). The latter is an interesting lead for advancing extraction methodologies. They also show that, on average vihno da jurema traditional preparations contain twice as much dmt compared to ayahuasca (Table 4) (even though this does not always correlate with how much dmt you take in a session)

I think that it is no surprise that dmt is in ayahuasca and in vinho da jurema, which makes this aspect of the study redundant. I would have liked them to expand on the vinho da jurema, as this is not supposed to have any added ingredients (as caapi is for ayahuasca) for MAO inhibition and our knowledge of why vihno da jurema is active as is, is very limited.