Chromatography detector

A chromatography detector is a device that detects and quantifies separated compounds as they elute from the chromatographic column. These detectors are integral to various chromatographic techniques, such as gas chromatography, ^[1] liquid chromatography, and high-performance liquid chromatography, ^[2] and supercritical fluid chromatography ^[3] among others. The main function of a chromatography detector is to translate the physical or chemical properties of the analyte molecules into measurable signal, typically electrical signal, that can be displayed as a function of time in a graphical presentation, called a chromatograms. Chromatograms can provide valuable information about the composition and concentration of the components in the sample.

Detectors operate based on specific principles, including optical, electrochemical, thermal conductivity, fluorescence, mass spectrometry, and more. Each type of detector has its unique capabilities and is suitable for specific applications, depending on the nature of the analytes and the sensitivity and selectivity required for the analysis.

There are two general types of detectors: destructive and non-destructive. The destructive detectors perform continuous transformation of the column effluent (burning, evaporation or mixing with reagents) with subsequent measurement of some physical property of the resulting material (plasma, aerosol or reaction mixture). The non-destructive detectors are directly measuring some property of the column eluent (for example, ultraviolet absorption) and thus affords greater analyte recovery.

Destructive detectors

In liquid chromatography:

• Charged aerosol detector electrically charged aerosol is used for the detection of non-UV-absorbing chargeable molecules, especially saccharides and lipids ^{[4] [5] [6]}
• Evaporative light scattering detector evaporating non volatile solutes inside a volatile mobile phase for universal detection. used for saccharides and lipids and other non-UV-absorbing molecules ^{[7] [8]}

In gas chromatography: ^[9]

• Flame ionization detector which uses ionizing flame to detect most hydrocarbon molecules ^{[10] [11] [12]}
• Flame photometric detector which uses atomizing flame to get light emitted from specific elements to detect and quantify them ^{[13] [14] [15]}
• Nitrogen Phosphorus Detector a thermionic detector with photometeric detection, sensitive specifically to nitrogen and phosphorus hydrocarbons ^[16]
• Atomic-emission detector is a hyphenation between gas chromatography and atomic emission spectrophotometer for detection of elements. ^{[17] [18]}

In all types of chromatography:

• Mass spectrometer ^[19] is in fact hyphenation between the separative instrument and a mass spectrometry instrument to get information on the molecular weight or atomic weight of the solute. In the advanced mass spectrometry technologies there is information on solutes structure and even chemical properties. The hyphenation between ultra high performance chromatography ^[20] with high resolution mass spectrometers ^[21] revolutionalized entire new scientific fields of research and application, such as toxicology, proteomics, lipidomics, genomics, metabolomics and metabonomics. ^[22]

Non-destructive detectors

Non-destructive detectors in liquid chromatography: ^[23]

• Ultraviolet light detectors, fixed or variable wavelength, which includes diode array detectors. The ultraviolet light absorption of the effluent is continuously measured at single or multiple wavelengths. These are by far most popular detectors for liquid chromatography. ^{[24] [25]}
• Fluorescence detector. Irradiates the effluent with a light of set wavelength and measure the fluorescence of the effluent at a single or multiple wavelength. ^[26]
• Refractive index detector. ^[27] Continuously measures the refractive index of the effluent. The lowest sensitivity of all detectors. Often used in size exclusion chromatography for polymer analysis. ^[28]
• Radio flow detector. Measures radioactivity of the effluent. This detector can be destructive if a scintillation cocktail is continuously added to the effluent.
• Chiral detector continuously measures the optical angle of rotation of the effluent. It is used only when chiral compounds are being analyzed. ^[29]
• Conductivity monitor. ^[23] Continuously measures the conductivity of the effluent. Used only when conductive eluents (water or alcohols) are used.

Non-destructive detectors in gas chromatography: ^[30]

• Thermal conductivity detector: ^[31] measures the thermal conductivity of the eluent.
• Electron capture detector: ^{[32] [33]} the most sensitive detector known. Allows for the detection of organic molecules containing halogen, nitro groups etc.
• Photoionization detector ^[34] measures the increase in conductivity achieved by ionizing the effluent gas with ultraviolet light radiation.
• Olfactometric detector: ^[35] assesses the odor activity of the eluent using human assessors.
• Electronic nose detector ^[36] which mimics human nose is emerging as a modern and advanced version of the olfactory detection is the electronic nose detector. ^[37]

References

1. Adlard, E.R.; Juvet, R.S. (January 1975). "A Review of Detectors for Gas Chromatography Part I: Universal Detectors" . C R C Critical Reviews in Analytical Chemistry. 5 (1): 03–13. doi:10.1080/10408347508542678. ISSN   0007-8980.
2. Swartz, Michael (2010-07-13). "HPLC Detectors: A Brief Review" . Journal of Liquid Chromatography & Related Technologies. 33 (9–12): 1130–1150. doi:10.1080/10826076.2010.484356. ISSN   1082-6076. S2CID   39911656.
3. West, Caroline (2018-10-01). "Current trends in supercritical fluid chromatography" . Analytical and Bioanalytical Chemistry. 410 (25): 6441–6457. doi:10.1007/s00216-018-1267-4. ISSN   1618-2650. PMID   30051210. S2CID   51725022.
4. Vehovec, Tanja; Obreza, Aleš (2010-03-05). "Review of operating principle and applications of the charged aerosol detector" . Journal of Chromatography A. 1217 (10): 1549–1556. doi:10.1016/j.chroma.2010.01.007. ISSN   0021-9673. PMID   20083252.
5. Schilling, Klaus; Holzgrabe, Ulrike (2020-05-24). "Recent applications of the Charged Aerosol Detector for liquid chromatography in drug quality control" . Journal of Chromatography A. 1619 460911. doi:10.1016/j.chroma.2020.460911. ISSN   0021-9673. PMID   32007219. S2CID   211015385.
6. Ghosh, Rajarshi; Kline, Paul (2019-05-14). "HPLC with charged aerosol detector (CAD) as a quality control platform for analysis of carbohydrate polymers". BMC Research Notes. 12 (1): 268. doi: 10.1186/s13104-019-4296-y . ISSN   1756-0500. PMC   6518655 . PMID   31088532.
7. Dreux, M.; Lafosse, M. (1995-01-01), El Rassi, Ziad (ed.), "Chapter 13 Evaporative Light Scattering Detection of Carbohydrates in HPLC" , Journal of Chromatography Library, Carbohydrate Analysis, vol. 58, Elsevier, pp. 515–540, doi:10.1016/s0301-4770(08)60518-7, ISBN   9780444899811 , retrieved 2023-10-21
8. Nayak, V. S.; Tan, Z.; Ihnat, P. M.; Russell, R. J.; Grace, M. J. (2012-01-01). "Evaporative Light Scattering Detection Based HPLC Method for the Determination of Polysorbate 80 in Therapeutic Protein Formulations". Journal of Chromatographic Science. 50 (1): 21–25. doi:10.1093/chromsci/bmr015. ISSN   0021-9665. PMC   3252124 . PMID   22291052.
9. Scott, Raymond P. W. (1996). Chromatographic detectors: design, function, and operation. Chromatographic science series. New York, NY: Dekker. ISBN   978-0-8247-9779-9.
10. "Gas Chromatography (GC) with Flame-Ionization Detection".
11. Zhou, Jia; Lu, Xiaoqing; Tian, Baoxia; Wang, Chonglong; Shi, Hao; Luo, Chuping; Li, Xiangqian (2020). "A gas chromatography-flame ionization detection method for direct and rapid determination of small molecule volatile organic compounds in aqueous phase". 3 Biotech. 10 (12): 520. doi:10.1007/s13205-020-02523-8. ISSN   2190-572X. PMC   7655889 . PMID   33194524.
12. Ševĉík, Jiří, ed. (1976-01-01), "5. The Flame Ionization Detector (FID)" , Journal of Chromatography Library, Detectors In Gas Chromatography, vol. 4, Elsevier, pp. 87–104, doi:10.1016/s0301-4770(08)60433-9, ISBN   9780444998576 , retrieved 2023-10-21
13. Ferguson, D. A.; Luke, L. A. (1979-04-01). "Critical appraisal of the flame photometric detector in petroleum analysis" . Chromatographia. 12 (4): 197–203. doi:10.1007/BF02411361. ISSN   1612-1112. S2CID   97533335.
14. Ševĉík, Jiří, ed. (1976-01-01), "9. The Flame Photometric Detector (FPD)" , Journal of Chromatography Library, Detectors In Gas Chromatography, vol. 4, Elsevier, pp. 145–164, doi:10.1016/s0301-4770(08)60437-6, ISBN   9780444998576 , retrieved 2023-10-21
15. Cheskis, Sergey.; Atar, Eitan.; Amirav, Aviv. (1993-03-01). "Pulsed-flame photometer: a novel gas chromatography detector" . Analytical Chemistry. 65 (5): 539–555. doi:10.1021/ac00053a010. ISSN   0003-2700.
16. Burgett, Charles A.; Smith, Douglas H.; Bente, H. Bryan (1977-04-01). "The nitrogen-phosphorus detector and its applications in gas chromatography" . Journal of Chromatography A. 134 (1): 57–64. doi:10.1016/S0021-9673(00)82569-8. ISSN   0021-9673.
17. Wylie, P. L.; Quimby, B. D. (1989). "Applications of gas chromatography with an atomic emission detector" . Journal of High Resolution Chromatography. 12 (12): 813–818. doi:10.1002/jhrc.1240121210. ISSN   0935-6304.
18. van Stee, Leo L. P.; Brinkman, Udo A. Th.; Bagheri, Habib (2002-09-10). "Gas chromatography with atomic emission detection: a powerful technique" . TrAC Trends in Analytical Chemistry. 21 (9): 618–626. doi:10.1016/S0165-9936(02)00810-5. ISSN   0165-9936.
19. Harvey, David J. (2021-01-01), Poole, Colin F. (ed.), "Mass spectrometric detectors for gas chromatography" , Gas Chromatography (Second Edition), Handbooks in Separation Science, Amsterdam: Elsevier, pp. 399–424, doi:10.1016/b978-0-12-820675-1.00022-8, ISBN   978-0-12-820675-1, S2CID   235010743 , retrieved 2023-10-21
20. Cielecka-Piontek, Judyta; Zalewski, Przemysław; Jelińska, Anna; Garbacki, Piotr (2013). "UHPLC: The Greening Face of Liquid Chromatography". Chromatographia. 76 (21–22): 1429–1437. doi:10.1007/s10337-013-2434-6. ISSN   0009-5893. PMC   3825615 . PMID   24273332.
21. Maurer, Hans H. (2013-05-31). "What is the future of (ultra) high performance liquid chromatography coupled to low and high resolution mass spectrometry for toxicological drug screening?" . Journal of Chromatography A. State-of-the art of (UHP)LC--MS(--MS) techniques and their practical application. 1292: 19–24. doi:10.1016/j.chroma.2012.08.069. ISSN   0021-9673. PMID   22964051.
22. Zaikin, V. G.; Borisov, R. S. (2021-12-01). "Mass Spectrometry as a Crucial Analytical Basis for Omics Sciences". Journal of Analytical Chemistry. 76 (14): 1567–1587. doi:10.1134/S1061934821140094. ISSN   1608-3199. PMC   8693159 .
23. R.P.W. Scott (1 February 1986). Liquid Chromatography Detectors. Elsevier. pp. 2–. ISBN   978-0-08-085836-4 . Retrieved 2 September 2013.
24. Logan, Barry K. (1994-03-30). "Liquid chromatography with photodiode array spectrophotometric detection in the forensic sciences" . Analytica Chimica Acta. 288 (1): 111–122. Bibcode:1994AcAC..288..111L. doi:10.1016/0003-2670(94)85120-4. ISSN   0003-2670.
25. W. John Lough; Irving W. Wainer (1995). High Performance Liquid Chromatography: Fundamental Principles and Practice. Blackie Academic & Professional. pp. 120–. ISBN   978-0-7514-0076-2 . Retrieved 2 September 2013.
26. Lingeman, H.; Underberg, W. J. M.; Takadate, A.; Hulshoff, A. (1985). "Fluorescence Detection in High Performance Liquid Chromatography" . Journal of Liquid Chromatography. 8 (5): 789–874. doi:10.1080/01483918508067120. ISSN   0148-3919.
27. Al-Sanea, Mohammad M.; Gamal, Mohammed (2022-07-01). "Critical analytical review: Rare and recent applications of refractive index detector in HPLC chromatographic drug analysis" . Microchemical Journal. 178 107339. doi:10.1016/j.microc.2022.107339. ISSN   0026-265X. S2CID   247277480.
28. Hong, Mei; Liu, Wei; Liu, Yonggang; Dai, Xuemin; Kang, Yu; Li, Rui; Bao, Feng; Qiu, Xuepeng; Pan, Yanxiong; Ji, Xiangling (2022-11-08). "Improved characterization on molecular weight of polyamic acids using gel permeation chromatography coupled with differential refractive index and multi-angle laser light scattering detectors" . Polymer. 260 125370. doi:10.1016/j.polymer.2022.125370. ISSN   0032-3861. S2CID   252578680.
29. Bobbitt, Donald R.; Linder, Sean W. (2001-03-01). "Recent advances in chiral detection for high performance liquid chromatography" . TrAC Trends in Analytical Chemistry. 20 (3): 111–123. doi:10.1016/S0165-9936(00)00083-2. ISSN   0165-9936.
30. McNair, Harold Monroe; Miller, James M.; Snow, Nicholas H. (2019). Basic gas chromatography (3rd ed.). Hoboken, NJ: John Wiley & Sons, Inc. ISBN   978-1-119-45073-3.
31. Rastrello, Fabio; Placidi, Pisana; Scorzoni, Andrea; Cozzani, Enrico; Messina, Marco; Elmi, Ivan; Zampolli, Stefano; Cardinali, Gian Carlo (May 2013). "Thermal Conductivity Detector for Gas Chromatography: Very Wide Gain Range Acquisition System and Experimental Measurements". IEEE Transactions on Instrumentation and Measurement. 62 (5): 974–981. Bibcode:2013ITIM...62..974R. doi:10.1109/TIM.2012.2236723. ISSN   0018-9456. S2CID   33546808.
32. Wentworth, W.E.; Chen, E.C.M. (1981), Chapter 3 Theory of electron capture , Journal of Chromatography Library, vol. 20, Elsevier, pp. 27–68, doi:10.1016/s0301-4770(08)60127-x, ISBN   9780444419545 , retrieved 2023-10-21
33. Zlatkis, A.; Poole, C.F. (1981). Electron Capture: Theory and Practice in Chromatography. Elsevier. p. 428.
34. Driscoll, J. N. (1985-11-01). "Review of Photoionization Detection in Gas Chromatography: The First Decade" . Journal of Chromatographic Science. 23 (11): 488–492. doi:10.1093/chromsci/23.11.488. ISSN   0021-9665.
35. Brattoli, Magda; Cisternino, Ezia; Dambruoso, Paolo Rosario; De Gennaro, Gianluigi; Giungato, Pasquale; Mazzone, Antonio; Palmisani, Jolanda; Tutino, Maria (2013). "Gas Chromatography Analysis with Olfactometric Detection (GC-O) as a Useful Methodology for Chemical Characterization of Odorous Compounds". Sensors. 13 (12): 16759–16800. Bibcode:2013Senso..1316759B. doi: 10.3390/s131216759 . ISSN   1424-8220. PMC   3892869 . PMID   24316571.
36. Kim, Chuntae; Lee, Kyung Kwan; Kang, Moon Sung; Shin, Dong-Myeong; Oh, Jin-Woo; Lee, Chang-Soo; Han, Dong-Wook (2022-08-19). "Artificial olfactory sensor technology that mimics the olfactory mechanism: a comprehensive review". Biomaterials Research. 26 (1): 40. doi: 10.1186/s40824-022-00287-1 . ISSN   2055-7124. PMC   9392354 . PMID   35986395.
37. Song, Jianxin; Chen, Qinqin; Bi, Jinfeng; Meng, Xianjun; Wu, Xinye; Qiao, Yening; Lyu, Ying (2020-11-30). "GC/MS coupled with MOS e-nose and flash GC e-nose for volatile characterization of Chinese jujubes as affected by different drying methods" . Food Chemistry. 331 127201. doi:10.1016/j.foodchem.2020.127201. ISSN   0308-8146. PMID   32562976. S2CID   219959356.