**11. Hyphenated separation techniques and its application in clinical chemistry**

The hyphenated techniques improved detection limits, sample identification capability, and miniaturization potential; hence, about 60% of the application of electrochemical detection (ED) has been found in the field of bioanalysis. The principle of ED used in biomedical analysis is a transfer of charge between substances in a column effluent and a working electrode; mainly, two types of ED either coulometric detection or amperometric detection are frequently used. The main advantages of using ED are the selectivity and sensitivity over UV-Vis detection. In HPLC, most of the application has been carried out by using UV-Vis detector, and ED is only used in small portion. The development of HPLC with ED facilitated highly sensitive and selective determination of homovanillic acid (HVA) and vanillylmandelic acid (VMA) in urine for the differential diagnosis of neuroblastoma pheochromocytoma and related tumors [45]. HPLC, coupled with UV-Vis using photodiode array as a detector, is widely used for determination of different drugs in serum. Other applications include determination of vitamins, antioxidants, and other components in biological samples.

CE coupled with MS provides an advantage of the sensitivity (parts per million range) and selectivity of these detection systems [46]. A detector that is becoming more frequently attached to CE is inductively coupled plasma mass spectrometry (ICP-MS). To date, CE-ICP-MS has been performed using a quadrupole detector within the MS allowing a small number of elements to be analyzed at any one time [47].

#### **12. Lab on a chip (LoC)**

Lab on a chip is defined as a microform of analytical devices that assimilate numerous laboratory operations such as PCR and DNA sequencing into a single chip on a very small scale. Miniaturized version of LoC provides cost-efficiency, use of low-volume reagents, high parallelization, high diagnostic speed, high sensitivity, and high expandability [48].

On the other hand, chronic disease (CD) healthcare is experiencing few limitations owing to lengthy and costly diagnosis procedures. Rapid, reliable, and low-cost diagnostic tools at point-of-care (PoC) instrumentation are therefore on high demand. LoC technology has a high potential to enable improved biomedical applications [49, 50]. In this regard, research toward developing new LoC-based PoC systems for CD diagnosis is fast growing into a nascent area such as chronic respiratory diseases (CRD), diabetes, and chronic kidney diseases (CKD) [51].

**41**

*Advancement in Analytical and Bioanalytical Techniques as a Boon to Medical Sciences*

This chapter summarizes various non-separation and separation methods used for biomedical analysis. Although routine clinical methods indicate normal/ abnormal levels of bioanalytes in urine/blood, still they often lack specificity due to severe complex biological sample interferences. In this regard, sample cleanup and highly sensitive techniques have proven to be helpful for early-stage disease diagnosis [52, 53] and detecting medical abnormalities [54]. To date, an array of hyphenated techniques plays an important role in the determination of bioanalytes,

I would like to sincerely thank Prof. R.S. Dubey and Prof. S.S. Pandey for their

I would also like to thank the staffs of the central library, Banaras Hindu

University, Varanasi, India, for providing valuable books and journals.

extensive support and guidance in the completion of this book chapter.

The author has declared no conflict of interest.

NAG N-acetyl-beta-D-glucosaminidase

BMV bioanalytical method validation

SEM scanning electron microscopy

CLIA chemiluminescence immunoassay

HPLC high-performance liquid chromatography

UV-Vis ultraviolet-visible

LC liquid chromatography GC gas chromatography CE capillary electrophoresis MS mass spectrometry

CSF cerebrospinal fluid SPE solid-phase extraction SPME solid-phase microextraction MIP molecularly imprinted polymer CLSM confocal laser scanning microscopy TIRF total internal reflection fluorescence

RIA radioimmunoassay FIA fluoroimmunoassay EIA enzyme immunoassay

LIA liposome immunoassay

IR infrared NIR near infrared

*DOI: http://dx.doi.org/10.5772/intechopen.80279*

with improved selectivity and sensitivity.

**13. Conclusions**

**Acknowledgements**

**Conflict of interest**

**Thanks**

**Abbreviations**

*Advancement in Analytical and Bioanalytical Techniques as a Boon to Medical Sciences DOI: http://dx.doi.org/10.5772/intechopen.80279*
