Editing Microfluidics (section)

=== Photonics Lab on a Chip (PhLOC) ===
Due to the increase in safety concerns and operating costs of common analytic methods ([[Inductively coupled plasma mass spectrometry|ICP-MS]], [[Inductively coupled plasma atomic emission spectroscopy|ICP-AAS]], and [[Inductively coupled plasma atomic emission spectroscopy|ICP-OES]]<ref name=":7">{{Cite journal |last1=Kirsanov |first1=D. |last2=Babain |first2=V. |last3=Agafonova-Moroz |first3=M. |last4=Lumpov |first4=A. |last5=Legin |first5=A. |date=2012-03-01 |title=Combination of optical spectroscopy and chemometric techniques—a possible way for on-line monitoring of spent nuclear fuel (SNF) reprocessing |url=https://www.degruyter.com/document/doi/10.1524/ract.2012.1901/html |journal=Radiochimica Acta |language=en |volume=100 |issue=3 |pages=185–188 |doi=10.1524/ract.2012.1901|s2cid=101475605 }}</ref>), the Photonics Lab on a Chip (PhLOC) is becoming an increasingly popular tool for the analysis of actinides and nitrates in spent nuclear waste. The PhLOC is based on the simultaneous application of [[Raman spectroscopy|Raman]] and [[Ultraviolet–visible spectroscopy|UV-Vis-NIR]] spectroscopy,<ref name=":8">{{Cite journal |last1=Nelson |first1=Gilbert L. |last2=Lackey |first2=Hope E. |last3=Bello |first3=Job M. |last4=Felmy |first4=Heather M. |last5=Bryan |first5=Hannah B. |last6=Lamadie |first6=Fabrice |last7=Bryan |first7=Samuel A. |last8=Lines |first8=Amanda M. |date=2021-01-26 |title=Enabling Microscale Processing: Combined Raman and Absorbance Spectroscopy for Microfluidic On-Line Monitoring |url=https://pubs.acs.org/doi/10.1021/acs.analchem.0c04225 |journal=Analytical Chemistry |language=en |volume=93 |issue=3 |pages=1643–1651 |doi=10.1021/acs.analchem.0c04225 |pmid=33337856 |osti=1783814 |s2cid=229323758 |issn=0003-2700}}</ref> which allows for the analysis of more complex mixtures which contain several actinides at different oxidation states.<ref name=":9">{{Cite journal |last1=Mattio |first1=Elodie |last2=Caleyron |first2=Audrey |last3=Miguirditchian |first3=Manuel |last4=Lines |first4=Amanda M. |last5=Bryan |first5=Samuel A. |last6=Lackey |first6=Hope E. |last7=Rodriguez-Ruiz |first7=Isaac |last8=Lamadie |first8=Fabrice |date=May 2022 |title=Microfluidic In-Situ Spectrophotometric Approaches to Tackle Actinides Analysis in Multiple Oxidation States |url=http://journals.sagepub.com/doi/10.1177/00037028211063916 |journal=Applied Spectroscopy |language=en |volume=76 |issue=5 |pages=580–589 |doi=10.1177/00037028211063916 |pmid=35108115 |bibcode=2022ApSpe..76..580M |s2cid=246488502 |issn=0003-7028 |via=Sage Journals}}</ref> Measurements made with these methods have been validated at the bulk level for industrial tests,<ref name=":7" /><ref name=":10">{{Cite journal |last1=Bryan |first1=S. A. |last2=Levitskaia |first2=Tatiana G. |last3=Johnsen |first3=A. M. |last4=Orton |first4=C. R. |last5=Peterson |first5=J. M. |date=September 2011 |title=Spectroscopic monitoring of spent nuclear fuel reprocessing streams: an evaluation of spent fuel solutions via Raman, visible, and near-infrared spectroscopy |url=https://www.degruyter.com/document/doi/10.1524/ract.2011.1865/html |journal=Radiochimica Acta |language=en |volume=99 |issue=9 |pages=563–572 |doi=10.1524/ract.2011.1865 |s2cid=95632074 |issn=0033-8230}}</ref> and are observed to have a much lower variance at the micro-scale.<ref>{{Cite journal |last1=Nelson |first1=Gilbert L. |last2=Lines |first2=Amanda M. |last3=Bello |first3=Job M. |last4=Bryan |first4=Samuel A. |date=2019-09-27 |title=Online Monitoring of Solutions Within Microfluidic Chips: Simultaneous Raman and UV–Vis Absorption Spectroscopies |url=https://pubs.acs.org/doi/10.1021/acssensors.9b00736 |journal=ACS Sensors |language=en |volume=4 |issue=9 |pages=2288–2295 |doi=10.1021/acssensors.9b00736 |pmid=31434479 |s2cid=201275176 |issn=2379-3694}}</ref> This approach has been found to have molar extinction coefficients (UV-Vis) in line with known literature values over a comparatively large concentration span for 150 μL<ref name=":9" /> via elongation of the measurement channel, and obeys [[Beer–Lambert law|Beer's Law]] at the micro-scale for U(IV).<ref name=":11">{{Cite journal |last1=Rodríguez-Ruiz |first1=Isaac |last2=Lamadie |first2=Fabrice |last3=Charton |first3=Sophie |date=2018-02-20 |title=Uranium(VI) On-Chip Microliter Concentration Measurements in a Highly Extended UV–Visible Absorbance Linearity Range |url=https://pubs.acs.org/doi/10.1021/acs.analchem.7b05162 |journal=Analytical Chemistry |language=en |volume=90 |issue=4 |pages=2456–2460 |doi=10.1021/acs.analchem.7b05162 |pmid=29327582 |issn=0003-2700}}</ref> Through the development of a spectrophotometric approach to analyzing spent fuel, an on-line method for measurement of reactant quantities is created, increasing the rate at which samples can be analyzed and thus decreasing the size of deviations detectable within reprocessing.<ref name=":10" />

Through the application of the PhLOC, flexibility and safety of operational methods are increased. Since the analysis of spent nuclear fuel involves extremely harsh conditions, the application of disposable and rapidly produced devices (Based on castable and/or engravable materials such as PDMS, PMMA, and glass<ref>{{Cite journal |last1=Mattio |first1=Elodie |last2=Lamadie |first2=Fabrice |last3=Rodriguez-Ruiz |first3=Isaac |last4=Cames |first4=Beatrice |last5=Charton |first5=Sophie |date=2020-02-01 |title=Photonic Lab-on-a-Chip analytical systems for nuclear applications: optical performance and UV–Vis–IR material characterization after chemical exposure and gamma irradiation |url=https://doi.org/10.1007/s10967-019-06992-x |journal=Journal of Radioanalytical and Nuclear Chemistry |language=en |volume=323 |issue=2 |pages=965–973 |doi=10.1007/s10967-019-06992-x |bibcode=2020JRNC..323..965M |s2cid=209441127 |issn=1588-2780}}</ref>) is advantageous, although material integrity must be considered under specific harsh conditions.<ref name=":11" /> Through the usage of fiber optic coupling, the device can be isolated from instrumentation, preventing irradiative damage and minimizing the exposure of lab personnel to potentially harmful radiation, something not possible on the lab scale nor with the previous standard of analysis.<ref name=":9" /> The shrinkage of the device also allows for lower amounts of analyte to be used, decreasing the amount of waste generated and exposure to hazardous materials.<ref name=":9" />

Expansion of the PhLOC to miniaturize research of the full nuclear fuel cycle is currently being evaluated, with steps of the [[PUREX]] process successfully being demonstrated at the micro-scale.<ref name=":8" /> Likewise, the microfluidic technology developed for the analysis of spent nuclear fuel is predicted to expand horizontally to analysis of other actinide, lanthanides, and transition metals with little to no modification.<ref name=":9" />