**3. Separation approaches**

Analytes of interest in complex biological samples must be separated prior to mass spectrometric detection and analysis and chromatography is the most widely used separation method for biological samples prior to MS. A number of Companies, e.g. Chromsystems (https://www.chromsystems.com/), ThermoFisher Scientific (https://www.thermofisher.com/at/en/home/clinical/diagnostic-testing/ clinical-chemistry-drug-toxicology-testing/therapeutic-drug-monitoring.html), Biocrates (https://biocrates.com/) or BioRad (www.bio-rad.com) developed analytical systems for a broad range of analyses of important clinical parameters. Integrated HPLC–MS clinical systems were also developed but they never really did find broad acceptance. Sciex introduced the Topaz® system (https://www. businesswire.com/news/home/20170731005050/en/First-Fully-Integrated-LC-MS-System-for-Clinical-Diagnostics-Announce-by-SCIEX) and Thermo Fisher introduced the Cascadion SM lab analyzer (https://www.labmedica.com/aacc-2017/ articles/294770271/worlds-first-fully-integrated-lc-ms-ms-clinical-analyzer-unveiled.html) in order to lower the barriers of many laboratories to adopt LC–MS.

The hyphenation of chromatography and mass spectrometry has its primary values in relatively fast detection and analysis of multiple analytes in a single sample with high sensitivity and high selectivity - the key challenge and requirement to detect and quantify low-concentration analytes. Currently, the most widely used separation columns for the HPLC–MS in a clinical laboratory have an inner

**5**

*Introductory Chapter: A Tool for Aided Advanced Diagnostics and Deep View into Biological...*

diameter of 2 mm. The quality of electrospray is highly dependable on separation conditions, i.e. mobile phase, presence or absence of salts, flow speed, column's inner diameter, etc. In proteomics, the use of separation columns with 50 μm or 75 μm ID is state-of-the-art; however, the columns operated at a low flow rate of several hundreds of nanoliters/minute are still rare in clinical analysis although they can provide a significant increase of sensitivity. Currently, the use of nanoflow separation still cannot cope with the demand for high sample throughput and robustness in clinical applications. Currently, the closest compromise between sensitivity and throughput is the use of the microbore and the capillary columns of

A new and exciting application of mass spectrometry in the clinical environment is the use of "live-MS" during surgical operations. Further development of this approach will revolutionize the diagnostics and help surgeons in extracting e.g. tumors with higher accuracy and better prognosis for the patient following the surgery [3–5]. In addition of analyzing small molecules in a targeted approach, the mass spectrometry can be applied in a clinical laboratory for a more widely screening approaches, e.g. screening of the human metabolome. The metabolome shed a light on our biological life story, reviling changes and processes that happened due to our genetics and due to the influence of the environment and the lifestyle. The measurement, detection, and analysis of metabolites is a step towards profiling an individuals' metabolic profile at any given time. That information can help understanding and, eventually, predicting the impact of environmental factors on the health. Therefore, metabolomics, in combination with other omics methods is a potent

A number of analytical methods for mass spectrometry in clinical laboratories

The use of MS technology for measurement and analysis of clinically important peptides and protein biomarkers will definitively increase with further improving MS technology. It is clear that personalized medicine will become the major field of further development of targeted therapy and MS will be one of the major players in identifying both therapeutically targets and therapeutical agents. It is with great certainty that MS applications for evaluation of protein and peptide-based, or even the mRNA-based therapeutics, will play a crucial part for the quality control of the therapeutics, evaluating drug efficacy, or investigating therapeutic response. Another issue is the miniaturization of MS and LC–MS systems that can be used portable systems or be applied in smaller field-laboratories. Certain advances were already achieved on developing such devises [16–23] that are being used in a

To conclude, mass spectrometry is a powerful analytical technology that still has not developed her full potential for use in clinical laboratory although its' use is growing. Different mass spectrometry-based devices have been approved for screening newborns, identifying microbes and fungus in cultures of human cells or for detecting measuring the concentrations of drugs (therapeutic and illicit) in body fluids. The development of large and integrated HPLC–MS systems for detecting and measuring peptides or proteins in clinical laboratories is still waiting to happen but mass spectrometry has already gained access to all areas of medical

were developed during the recent past, and the development gains additional momentum as the CoVID-19 pandemics holds the mankind in grip and methods for

*DOI: http://dx.doi.org/10.5772/intechopen.97617*

300 μm – 500 μm and 1 mm – 2 mm inner diameter.

addition to developing personalized medical approaches.

fast HPLC–MS have been developed and applied [6–15].

**4. Clinical proteomics**

number of analyses.

research and diagnostics.

#### *Introductory Chapter: A Tool for Aided Advanced Diagnostics and Deep View into Biological... DOI: http://dx.doi.org/10.5772/intechopen.97617*

diameter of 2 mm. The quality of electrospray is highly dependable on separation conditions, i.e. mobile phase, presence or absence of salts, flow speed, column's inner diameter, etc. In proteomics, the use of separation columns with 50 μm or 75 μm ID is state-of-the-art; however, the columns operated at a low flow rate of several hundreds of nanoliters/minute are still rare in clinical analysis although they can provide a significant increase of sensitivity. Currently, the use of nanoflow separation still cannot cope with the demand for high sample throughput and robustness in clinical applications. Currently, the closest compromise between sensitivity and throughput is the use of the microbore and the capillary columns of 300 μm – 500 μm and 1 mm – 2 mm inner diameter.

A new and exciting application of mass spectrometry in the clinical environment is the use of "live-MS" during surgical operations. Further development of this approach will revolutionize the diagnostics and help surgeons in extracting e.g. tumors with higher accuracy and better prognosis for the patient following the surgery [3–5].

In addition of analyzing small molecules in a targeted approach, the mass spectrometry can be applied in a clinical laboratory for a more widely screening approaches, e.g. screening of the human metabolome. The metabolome shed a light on our biological life story, reviling changes and processes that happened due to our genetics and due to the influence of the environment and the lifestyle. The measurement, detection, and analysis of metabolites is a step towards profiling an individuals' metabolic profile at any given time. That information can help understanding and, eventually, predicting the impact of environmental factors on the health. Therefore, metabolomics, in combination with other omics methods is a potent addition to developing personalized medical approaches.

A number of analytical methods for mass spectrometry in clinical laboratories were developed during the recent past, and the development gains additional momentum as the CoVID-19 pandemics holds the mankind in grip and methods for fast HPLC–MS have been developed and applied [6–15].
