Related Experiment Video
Updated: Feb 13, 2026

Building Langmuir Probes and Emissive Probes for Plasma Potential Measurements in Low Pressure, Low Temperature Plasmas
Published on: May 25, 2021
Low-temperature plasma-probe mass spectrometry based method for determination of new psychoactive substances in oral
Xiaochen Wang1,2, Zhendong Hua3, Zhaoguang Yang2
1College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Rationale:
Owing to the widespread abuse of new psychoactive substances (NPSs), developing a rapid, easily operable method to detect NPSs in oral fluid is of high priority. Their ease of collection and non-invasive nature make oral fluid samples suitable for on-site tests and forensic cases. Herein we report a rapid and sensitive method to screen and quantitate 11 new NPSs in oral fluid.
Methods:
Low-temperature plasma-probe mass spectrometry (LTP-MS) was applied and, to improve the signal intensity, thermally assisted desorption was employed. Tandem mass spectrometry was performed to exclude false positive signals and to decrease noise at the m/z values of interest.
Results:
Linearity was studied using matrix-matched calibration curves; all the analytes exhibited good linearity with R2 varying from 0.9907 to 0.9981. The estimated limits of detection (LODs) were in the range of 3.0-15.2 ng/mL, which are comparable to those of immunoassay; relative standard deviations (RSDs) are no greater than 23% at the studied concentration levels.
Conclusions:
The proposed LTP-MS-based method was promising in forensic and on-site applications to curb the abuse of NPSs.
Related Concept Videos
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS): Interferences
Inductively Coupled Plasma–Mass Spectrometry (ICP–MS): Overview
Assessing Body Temperature - Oral
Step 1:
Start by practicing proper hand hygiene to prevent the spread of microorganisms.
Step 2:
Take the thermometer out of the charging unit, switch it on, and wait for the ready sign.
Step 3:
Gently slide the probe cover until a click is heard. This simple action prevents cross-contamination and ensures the correct placement of the probe cover.
Step 4:
Instruct the patient to open their mouth and place...
Mass Spectrometry: Overview
Tandem Mass Spectrometry
Mass Spectrometry of Amines

