Ambient Ionization and Miniature Mass Spectrometry Systems for Disease Diagnosis and Therapeutic Monitoring

Rapid Comm Mass Spectrometry

Tian

Aliang

et al. 2020

Rationale Dopant‐assisted photoionization (PI) has been widely used in the mass spectrometric analysis of volatile compounds. Exploring simple doping methods will benefit parameter optimization and promote the application of this technique. Methods A previously built miniature ion trap mass spectrometer was used to study dopant‐assisted vacuum PI. The sampling system of this device was modified to provide three inlets for the simultaneous introduction of analytes, dopants, and auxiliary air. Then, dopant solution was directly injected into the ion trap chamber through a self‐aspirating capillary inlet and rapidly evaporated without heating. Various dopant solutions were prepared and switched during the experiments. Results When analyzing some aniline compounds, the signals of all analytes were improved by more than 10 times after the injection of 2% anisole solution as a dopant. In addition, anisole can provide analyte signals more than three times stronger than those provided by the other dopants. On the basis of the ionization energy selectivity of dopant‐assisted PI, some isomers in the mass spectrometric analysis were distinguished using different additives. Conclusions In general, liquid doping is as feasible and as effective as other traditional methods, and using appropriate dopants with high PI efficiency or feeding more dopants contributes to the ionization of analytes. The proposed method also offers several unique merits, such as simple operation, low consumption, and smooth switching with minimal residue.

Section: Introductionmentioning

confidence: 99%

Implementation and study of dopant‐assisted photoionization with a miniature capillary inlet ion trap mass spectrometer

Rapid Comm Mass Spectrometry

Tian

Aliang

et al. 2020

“…Currently, the emergence of a variety of novel sampling and ionization approaches, along with the continuous updating of highperformance instruments, have extended the application of mass spectrometers to various online and on-site analysis elds such as food safety, 1,2 environmental monitoring, 3 and clinical diagnostics. 4 As these areas all have a strong need for rapid time response, the prosperity of ambient ionization [5][6][7][8][9] technology can well satisfy such demands by greatly simplifying the sample preparation process to improve the detection efficiency.…”

Section: Introductionmentioning

confidence: 99%

“…Besides these two representatives, other ambient ionization techniques, such as secondary electrospray ionization (SESI), [12][13][14][15] extractive electrospray ionization (EESI), 16 paper spray (PS) 17,18 and dielectric barrier discharge ionization (DBDI), 19 are also driving mass spectrometry to conquer more and more application territories. [4][5][6][7][8][9]20 Among these ionization methods, SESI has been proposed for more than two decades, and its recent use in some refreshing applications like breath analysis [21][22][23] and plant metabolism study 24,25 is regaining increasing attention to this technique.…”

Section: Introductionmentioning

confidence: 99%

Exploiting the native inspiratory ability of a mass spectrometer to improve analysis efficiency

Lin

et al. 2020

RSC Adv.

“…Mass spectrometry (MS) is one of the most powerful analytical tools and it has been widely used in numerous fields. To meet increasing demands of rapid and on‐the‐spot analysis, miniaturization and portability have recently become a major area of mass spectrometer development . The development of a miniature mass spectrometer must be based on the miniaturization of all individual components, including the mass analyzer, the ionization source, the pumping system, the power supply, the control system, and so on .…”

Section: Introductionmentioning

confidence: 99%

“…To meet increasing demands of rapid and on-the-spot analysis, miniaturization and portability have recently become a major area of mass spectrometer development. 1,2 The development of a miniature mass spectrometer must be based on the miniaturization of all individual components, including the mass analyzer, the ionization source, the pumping system, the power supply, the control system, and so on. 3 As the first step of the MS analysis, introduction of samples or ions in the field is the first barrier that should be overcome for fast and direct analysis using a miniature instrument, in which small vacuum pumps with limited pumping capacity are mostly employed.…”

Section: Introductionmentioning

confidence: 99%

Pulsed capillary introduction applied to a miniature mass spectrometer for efficient liquid analysis

Shi

Rapid Comm Mass Spectrometry

et al. 2018

Rationale Capillary sampling of liquids for direct mass spectrometry (MS) analysis is introduced. The low transfer rate of the solution in the capillary will affect the analytical sensitivity and the response time; hence a pulsed capillary introduction (PCI) method was proposed and characterized. Methods The experiments were carried out using a miniature quadrupole mass spectrometer, and liquid can be spontaneously drawn into the vacuum chamber for subsequent ionization and detection. A simple up‐and‐down motor platform was used to control the brief contact of the capillary inlet with the liquid sample and implement pulsed injection. The pulsed sampling parameters were optimized based on the characterization and dynamic study of liquid transfer in capillaries. Results Compared with continuous capillary introduction (CCI), PCI can reduce the response time of MS analysis from more than half a minute to a few seconds. In addition, it provides better detection sensitivity as the ion signals of all solution components are enhanced and the acquired limit of detection (LOD) of toluene is about eight times lower than CCI analysis. For each analysis, the consumed sample volume is only a few nanoliters and the absolute consumption of the analyte can reach the femtogram level. Conclusions The proposed PCI method is proved to be successful in improving the sampling efficiency when performing direct liquid analysis without increasing the vacuum load. A miniature MS instrument with a proper capillary inlet can possess flexible operation modes to meet different application demands.