New Strategy for Further Improving the Detection Sensitivity of Direct Analysis in Real Time-Mass Spectrometry

Ambient mass spectrometry facilitates surface detection under ambient conditions and has quickly found its applications in various areas.However,the sensitivity of AMS methods is usually not as good as that of encapsulated ion sources due to less efficient ion transmission.In this work,a briefly machined external ion funnel(threepole electrostatic lens)was adopted and installed between direct analysis in real time and the mass spectrometer inlet to increase detection sensitivity.Software investigation with SIMION version 8.0 was employed to calculate electric fields and to simulate the trajectories of charged particles in the electric field.Both the geometrical parameters of the ion funnel and the electric parameters were studied to obtain the optimal ion focusing results,which demonstrated the ion funnel equipment would greatly improve the ion transmission efficiency.The equipment showed good prospect in direct analysis in real time-mass spectrometry analysis in the future.

Metabolomic Fingerprinting of Blood Samples by Direct Infusion Mass Spectrometry:Application in Alzheimer’s Disease Research

Metabolomics is largely employed in numerous biomedical research fields,such as the study of the underlying pathology of diseases,discovery of diagnostic biomarkers,or drug development.Nowadays,the main challenge is to obtain comprehensive and unbiased metabolomic profiles due to the huge complexity,heterogeneity,and dynamism of the metabolome.To this end,mass spectrometry represents a very interesting analytical platform,since the complexity of metabolome may be overcome through the use of different orthogonal separation techniques,including liquid chromatography,gas chromatography,and capillary electrophoresis.Alternatively,direct mass spectrometry analysis has been postulated as a complementary choice to hyphenated approaches.This technique exhibits several advantages such as the ability for high-throughput screening,fast analysis,and wide metabolomic coverage,since there is not exclusion of compounds due to the separation device.The present work explores the utility of metabolomics based on direct infusion mass spectrometry for analyzing blood samples.The most important analytical concerns to be considered are discussed,including sample handling,comprehensive fingerprinting,as well as subsequent identification of metabolites,and global characterization of metabolomic profiles.To conclude,a brief review on the application of these metabolomic platforms in Alzheimer’s disease research is also provided.

Metabolomic Fingerprinting of Blood Samples by Direct Infusion Mass Spectrometry:Application in Alzheimer’s Disease Research

Metabolomics is largely employed in numerous biomedical research fields,such as the study of the underlying pathology of diseases,discovery of diagnostic biomarkers,or drug development.Nowadays,the main challenge is to obtain comprehensive and unbiased metabolomic profiles due to the huge complexity,heterogeneity,and dynamism of the metabolome.To this end,mass spectrometry represents a very interesting analytical platform,since the complexity of metabolome may be overcome through the use of different orthogonal separation techniques,including liquid chromatography,gas chromatography,and capillary electrophoresis.Alternatively,direct mass spectrometry analysis has been postulated as a complementary choice to hyphenated approaches.This technique exhibits several advantages such as the ability for high-throughput screening,fast analysis,and wide metabolomic coverage,since there is not exclusion of compounds due to the separation device.The present work explores the utility of metabolomics based on direct infusion mass spectrometry for analyzing blood samples.The most important analytical concerns to be considered are discussed,including sample handling,comprehensive fingerprinting,as well as subsequent identification of metabolites,and global characterization of metabolomic profiles.To conclude,a brief review on the application of these metabolomic platforms in Alzheimer’s disease research is also provided.

Rapid Screening of Nine Illicit Drugs in Human Blood and Urine by Direct Analysis in Real‑Time Mass Spectrometry

We aimed to establish for the rapid detection of morphine,O6‑monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin in human blood and urine by direct analysis in real‑time coupled with tandem mass spectrometry(DART‑MS/MS).These samples were extracted by acetonitrile‑methanol(V/V=4:1),using DART 12 Dip‑it automatic sampling system.They were injected at 400℃,and analyzed by positive ion and multiple reaction monitoring mode.The detection limits of morphine,O6‑Monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin were 100,50,50,100,20,20,10,1,and 0.01 ng/mL,respectively.The practical cases contained methamphetamine,codeine,cocaine,and O6‑monoacetylmorphine were detected accurately and rapidly.The method has the advantages of high sensitivity and good accuracy.The sample processing is simple and can be analyzed in a short time.This method is suitable for the analysis of morphine,O6‑monoacetylmorphine,heroin,codeine,cocaine,methamphetamine,ketamine,methadone,and dolantin in some practical cases.