China
Africa
Explore chapters and articles related to this topic
Emerging Biomedical Analysis
Published in Lawrence S. Chan, William C. Tang, Engineering-Medicine, 2019
Many variants of ESI have been developed in recent years. Ambient ionization is a family of techniques that was derived from ESI to enable rapid MS analysis at lower cost. Ambient ionization techniques generate ions under ambient conditions for subsequent MS analysis directly on the sample with minimum sample preparation (Cooks et al. 2006, Nyadong et al. 2007). Representative ambient ionization techniques are desorption electrospray ionization (DESI) and direct analysis in real time (DART). In the DESI technique, an electrospray of charged solvent droplets hits the sample surface and extracts analyte molecules to form secondary droplets (Fig. 2). The secondary droplets undergo a similar ionization process with ESI and eventually are delivered to the inlet of a mass spectrometer (Takats et al. 2004). In the DART methodology, an electrical potential is applied to a helium gas stream to generate metastable species. These excited-state gas molecules subsequently react with the analyte surface to form ions (Cody et al. 2005). Due to the simple and cost-effective experimental setup, DESI, DART and other ambient ionization techniques, such as paper spray ionization, liquid microjunction surface sampling probe (LMJ-SSP) and rapid evaporative ionization mass spectrometry (REIMS), were used in several clinical studies (Li et al. 2017). Examples of clinical applications of ambient ionization MS will be discussed later in this chapter.
Emerging role of metabolomics in protein conformational disorders
Published in Expert Review of Proteomics, 2021
Nimisha Gupta, Sreelakshmi Ramakrishnan, Saima Wajid
Parkinson’s disease (PD) is another neurodegenerative disorder that leads to stiffness, shaking, and difficulty with balancing, walking, and coordination [62]. The prevalence of PD is reported to be approx 1% in the 60+ years age group and increases to 3% in the 80 years and above age group. According to statistical analysis, the incidence rate of PD is higher in males than in females [63]. The pathogenesis of PD is associated with alpha-synuclein aggregation in Lewy bodies and neuronal loss [62]. The cause of PD is not fully understood. However, many studies carried out at the metabolomic level using CSF, blood, and plasma have provided some insight into the cause of PD [62,64]. Gill et al. (2018) demonstrated a new technique (ambient ionization technique) that does not require lengthy sample preparation and provides an opportunity for rapid analysis. Ambient ionization technique includes laser ablation electrospray ionization, liquid microinjection surface sampling, and desorption electrospray ionization. Besides, nano-spray desorption electrospray ionization was used by Bergman et al. (2018) to quantify neurotransmitters in rat brain tissue [65].
Mass spectrometry in emergency toxicology: Current state and future applications
Published in Critical Reviews in Clinical Laboratory Sciences, 2019
Xander M. R. Van Wijk, Robert Goodnough, Jennifer M. Colby
Another advance in technology that may be of use is ambient ionization, which researchers suggest could be used to directly sample biofluids at the point of care [94–97]. This technique requires very limited sample pretreatment and consequently has a very fast time to result. Ambient ionization could be used at the point of care, for example in the ED, or samples could be sent to a central lab for testing. Analysis times are very short, typically less than 5 min, and a variety of different compounds can be analyzed. Development of the collection kits that would be required to obtain and directly introduce biosamples into the mass spectrometer would be necessary for clinical adoption of this technique. Ambient ionization techniques are currently in use in other disciplines, and though this technique has not been tested in clinical practice, it shows promise as a way to streamline sample preparation and reduce TAT.
Paper spray ionization mass spectrometry: recent advances and clinical applications
Published in Expert Review of Proteomics, 2018
Spencer Chiang, Wenpeng Zhang, Zheng Ouyang
Since its inception, paper spray has been one of the most widely used ambient ionization methods. Its simplicity, ease-of-use and amenability to analyzing complex biofluids have made it an ideal candidate as a significant ionization alternative. Xenobiotic analysis has been well characterized with numerous studies showing significant levels of sensitivity (as low as sub-ppt levels) for quantitation and targeted analysis [10,12,42]. Similarly, recent advancements in analyzing endogenous biomolecules, which traditionally had been challenging for PS-MS, have reported preliminary investigations quantifying significant metabolites and lipid profiling of tissue samples [27]. Developing a comprehensive PS-MS system that can be operated in a clinical setting could be greatly advantageous, providing patients with inexpensive, rapid biofluid diagnostics and monitoring. Despite its potential, PS-MS is still a relatively young analytical method; several issues still remain to be addressed before use in clinical applications.