Quantitative Recovery Research Articles

E‐PoSa: A novel and effective tool for sampling pollen directly from flowers

Abstract Pollinator insects are declining worldwide, also due to the alteration of their diet with severe implications on their health status. Pollinators diet relies mainly on flower rewards (i.e. pollen and nectar), and a precise characterization of their chemical composition is crucial in defining pollinators' nutritional ecology. In this context, the pollen represents a challenging source to investigate, especially due to operative challenges during collection operations and to the small amounts produced per flower. Here, we designed and tested a novel, easy‐to‐assemble tool for pollen sampling: E‐PoSa (Electronic Pollen Sampler), based on the use of a portable vacuum cleaner. We compared it with some of the most used sampling methods for pollen (i.e. anthers sieving and sampling of the whole anthers) by looking at the differences in their quantitative recovery and nutritional profile. Its applicability in ecological studies was also corroborated by an assessment of its recovery rate obtained from a panel of wildflower species in an operational environment. The data obtained showed a significantly higher pollen recovery capacity of E‐PoSa compared with the conventional sieving approach and the success in retrieving enough pollen to conduct phytochemical analyses from a broad range of flower morphologies in the field. Our results also demonstrated that high purity pollen can be collected with E‐PoSa and that the device does not introduce any significant variation in the nutritional analysis compared with the conventional sieving. This new sampling approach represents a cheap and easy‐to‐assemble tool encouraging its future use not only in the field of pollen nutrition but also in a wide variety of other contexts related to pollination ecology. Acknowledging the potential influences of the sampling techniques and moving towards shared standardized field protocols will advance the comprehension of species interactions and foraging patterns of pollinators and their nutritional needs.

Deep eutectic solvent liquid phase microextraction, powered by ultrasonic system, for determination of β-carotene in food samples

The research work is mainly concerned with the extraction of β-carotene, which is a terpenoid compound, from food and fruit samples using deep eutectic solvent based liquid phase extraction. Deep eutectic solvent liquid phase microextraction method, powered by ultrasonic mixing, (DES-UP-LPME) was carried out with deep eutectic solvent (DES) consisting of tetrabutylammoniumbromide (TBAB) and decanoic acid (DA). Key parameters such as pH, sample volume, tetrahydrofuran (THF) volume, DES type and volume, matrix effect, ultrasonication/centrifugation time were optimized to increase the extraction efficiency of β-carotene. Quantitative recoveries were obtained when pH, TBAB:DA ratio and sample volume were 3, 1:3 and 30, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.005 µg/mL and 0.015 µg/mL, respectively. Various food samples were analyzed spectrophotometrically by using the developed DES-UP-LPME at 450 nm. The addition/recovery studies were also performed on water samples to evaluate the accuracy of the method.

Solubilization mechanism and mass-transfer model of anionic-nonionic gemini surfactants for chlorinated hydrocarbons

Accurate prediction and modeling of the quantitative recovery of chlorinated hydrocarbons in an aquifer by anionic-nonionic gemini surfactants requires estimates of their mass-transfer models and capture mechanisms. In this work, a series of synthesized anionic-nonionic gemini surfactants (GEOnS-m) with different molecular structures were used to solubilize different chlorinated hydrocarbons that contaminate the aquifer. GEOnS-m aggregate showed vesicle, rodlike micelle, and spherical micelle as the ethylene oxide content (EO) number increases. Non-polar chlorinated hydrocarbons (PCE, CT) mainly solubilized in the hydrophobic interior of micelles, and polar chlorinated hydrocarbons (TCE, MCB) mainly solubilized in the “palisade layer” of micelles. Solubilization processes were followed employing first-order and second-order kinetics. The solubilization rate increases with the decrease of EO number of GEOnS-m molecules. In essence, lower interfacial tension reduces the mass-transfer resistance of chlorinated hydrocarbons at the two-phase interface. The diameter of vesicles and spherical micelles increases, and rodlike micelles evenly changed to vesicles as chlorinated hydrocarbons transfer into micelles. The solubilization process of GEOnS-m for chlorinated hydrocarbons conforms to a novel “oil diffusion & micelle reformation model” that represents the coupling to two pre-existing models. And the solubilization mass-transfer mathematical model demonstrated the solubilization mass-transfer coefficient is affected by the combination of surfactant and solubilized organic properties. This study advances the application of solubilization for chlorinated hydrocarbons using anionic-nonionic gemini surfactants in surfactant-enhanced aquifer remediation (SEAR) design.

Dispersive solid phase microextraction (DSP-μE) by using nanodiamond@Bi2MoO6 composite for the separation-preconcentration of Pb(II) in food and water samples

A nanodiamond@Bi2MoO6 nanocomposite was synthesized using a hydrothermal procedure. The nanodiamond@Bi2MoO6 was characterized using various techniques like BET, FT-IR, FESEM, EDX, and XRD. It was used as an adsorbent for dispersive solid phase microextraction (DSP-μE) of Pb(II) at ultra-trace levels prior to its flame atomic absorption spectrometric detection. The analytical parameters such as pH values, adsorbent dose, eluent concentration, eluent volume, eluent time, and sample volume on the quantitative recoveries of lead(II) on nanodiamond@Bi2MoO6 were optimized. Additionally, matrix effects were investigated. The LOD, LOQ, and PF were calculated as 1.75 μg L-1, 5.85 μg L-1 and 16.7, respectively. The validation of the DSP-μE procedure was checked by using certificated reference material (CRM) Wheat Gluten RM8418 and BCR Estuarine water 505 for satisfactory with 98.5 to 102.4 % recovery results. The new DSP-μE procedure was applied to be successful for Pb determination in instant noodles and water samples. The concentration of Pb(II) in instant noodles samples ranged between 23 and 194 µg kg−1. In water samples, Pb(II) concentration was observed in the range of 7.95–8.05 and 123.3–142.7 µg/L, tap water, and industrial water respectively. The estimated daily intake of total Pb(II) in the food (noodles/serving i.e., noodles, seasoning spices, water) was come out as 4.27– 16.12 µg kg−1 day−1 and compared with PTDI level.

Authenticity identification of animal species in characteristic milk by integration of shotgun proteomics and scheduled multiple reaction monitoring (MRM) based on tandem mass spectrometry

Milk is one of the oldest natural dairies with high value, which has different species including cow, camel, donkey, goat, sheep, buffalo, yak and et al. However, economically motivated adulteration of non-cow milk with cheaper cow milk occurs frequently. To develop a high-throughput approach for milk species authentication, integration of shotgun proteomics and scheduled multiple reaction monitoring (MRM) was developed. In total, 37 specific peptides were screened as unique to different species. Specific peptides processing stability was investigated under different treatment (heat, pressure, fermentation). Subsequently, four quantitative ion pairs of peptides from cow milk and six quantitative ion pairs of peptides from six non-cow milks were selected for the adulteration quantitative analysis. The method is capable of detection adulteration in the range of 1%–100%, and the quantitative recoveries ranged from 91.07% to 111.75%. The results suggested that combination of shotgun proteomics and MRM had potential for the milk species authentication.

Integrated paper/graphene 3D pop-up device for the quantitative sensing of carbaryl

A completely lab-made paper/graphene-based 3D pop-up device (3D-PP) for the analysis of carbaryl (CBR), a pesticide widely used in crop production, is proposed. The device is composed of a nitrocellulose sensor equipped with reduced graphene oxide (rGO) and a foldable 3D paper pop-up. The rationale of the device is based on 3D and 2D configurations to allow the whole analytical procedure. In the 3D arrangement sample pre-concentration and hydrolysis occur; after folding (2D), contact with the complementary nitrocellulose-based sensor is ensured. The sensor, constituted by nanostructured graphene film, allows to obtain the necessary electroanalytical performance. 3D-PP has been shaped and nanostructured using a CO2-laser plotter and finished using low-cost benchtop instruments, ensuring in-series manufacturing of the device modules. 3D-PP includes the main steps required for CBR determination, i.e. (i) pre-concentration/purification, (ii) hydrolysis, (iii) medium neutralization, and (iv) electrochemical detection. 3D-PP was challenged for CBR quantification in model solutions and different grain samples. The response linearity (1.5–33 μM) and LOD (0.4 μM) obtained ensures CBR determination at the European-law admitted maximum residue levels (MRL). As proof of applicability, to simulate contaminates samples, different grains (i.e. soft and durum wheat, kamut, and barley) were spiked, before extraction, with CBR at three concentration levels corresponding to 0.5x, 1x, and 1.5x MRL; in all cases, quantitative and reproducible recoveries were obtained (93–109%; RSD ≤ 6%, n = 3). 3D-PP is produced using cellulosic components and solvent-free approaches, includes all CBR analysis steps, and returns reliable results in 15 min, resulting portable and usable with a smartphone

Development of an automated flow chemistry affinity-based purification process for DNA-encoded chemistry

An automated flow chemistry platform for DNA-encoded library (DEL) technologies requires the integration of a purification process for DNA-tagged substrates. It facilitates the development of further DEL reactions, building block rehearsal, and library synthesis. Therefore, a recently developed, manual affinity-based batch purification process for DNA-tagged substrates based on dispersive solid-phase extraction (DSPE) was transferred to automated flow chemistry using tailored 3D-printed microfluidic devices and open-source lab automation equipment. The immobilization and purification steps use Watson–Crick base pairing for a compound-encoding single-stranded DNA, which allows for the thorough removal of impurities and contaminations by washing steps and operationally simple recovery of the purified DNA-encoded compounds. This work optimized the annealing step for flow incubation and DNA purification was accomplished by flow DSPE washing/elution steps. The manually performed batch affinity-based purification process was compared with the microfluidic process by determining qualitative and quantitative DNA recovery parameters. It aimed at comparing batch and flow purification processes with regard to DNA recovery and purity to benefit from the high potential for automation, precise process control, and higher information density of the microfluidic purification process for DNA-tagged substrates. Manual operations were minimized by applying an automation strategy to demonstrate the potential for integrating the microfluidic affinity-based purification process for DNA-tagged substrates into an automated DNA-encoded flow chemistry platform.Graphical

Signal-noise metrics for RNA binding protein identification reveal broad spectrum protein-RNA interaction frequencies and dynamics

Recent efforts towards the comprehensive identification of RNA-bound proteomes have revealed a large, surprisingly diverse family of candidate RNA-binding proteins (RBPs). Quantitative metrics for characterization and validation of protein-RNA interactions and their dynamic interactions have, however, proven analytically challenging and prone to error. Here we report a method termed LEAP-RBP (Liquid-Emulsion-Assisted-Purification of RNA-Bound Protein) for the selective, quantitative recovery of UV-crosslinked RNA-protein complexes. By virtue of its high specificity and yield, LEAP-RBP distinguishes RNA-bound and RNA-free protein levels and reveals common sources of experimental noise in RNA-centric RBP enrichment methods. We introduce strategies for accurate RBP identification and signal-based metrics for quantifying protein-RNA complex enrichment, relative RNA occupancy, and method specificity. In this work, the utility of our approach is validated by comprehensive identification of RBPs whose association with mRNA is modulated in response to global mRNA translation state changes and through in-depth benchmark comparisons with current methodologies.

Aptamers selected and identified as a colorimetric dual-mode sensing platform for selective and sensitive detection of capsaicin

Capsaicin (CAP), a prominent indicator, has been identified for detecting the gutter oil in adulterated edible oils. In view of the limited availability of efficient and reliable methods for detecting gutter oil, the present study employed the Capture-SELEX technology, which utilizes a high-throughput sequencing (HTS) platform, to facilitate the precise tracking of screening rounds and facilitate the isolation of aptamers with specific affinity for CAP. Isothermal titration calorimetry (ITC) determined the highest affinity and Kd value of 15.5 ± 4.69 nM for aptamer Cap-1. A colorimetric dual-mode aptasensor was designed for CAP detection based on graphene oxide (GO)@gold nanoparticles (AuNPs) composite. A high-sensitivity assay can be achieved using a Synergy™ H1 multimode zymography instrument and a smartphone. Under optimal conditions, the colorimetric dual-mode aptasensor has a detection range of 0.5 ∼ 120 ng mL−1 and a low limit of detection (LOD) of 0.14 ng mL−1. The quantitative recovery of the sensor for CAP in edible oil was 86.25∼98.12 %. Compared with the conventional single-mode aptasensor, the dual-mode aptasensor has independent signal conversion, which provides suitable detection solutions for different scenarios and improves detection accuracy and reliability.

Method development for analysis 13 per‐ and polyfluoroalkyl acids in tap water by HPLC‐MS/MS

AbstractThe purpose of this study was to develop a sensitive, accurate and simple method for analysis of 13 perfluoroalkyl acids (8 perfluoroalkyl carboxylic acids and 5 perfluoroalkyl sulfonic acids) in tap water by LC‐MS/MS. This paper focuses on optimizing the chromatographic instrumental operating parameters and the solid phase extraction conditions using HLB cartridges. Results from the method validation showed that the method has sub ng/L LOQs (0.10‐0.60 ng/L), quantitative recoveries at the concentrations near the LOQs (74.4‐122.8%) and high repeatability with acceptable %RSD (15.6‐38.3%). The analytical procedure was then applied to assess how significant the contamination of PFAAs in tap water of Ho Chi Minh City. Besides that, a new self‐made solid phase extraction material prepared by grafting an ionic liquid on silica was used to enrich the target analytes. Preliminary results show that the material based on 1‐octyl‐3‐(3‐(triethoxysilyl) propyl)‐1H‐imidazolium bromide has promising retention ability for these compounds, the recoveries on ionic liquid‐based materials ranged from 36.3‐69.0%.

Enhancing the Reliability of SERS Detection in Ampicillin Using Oriented Tetrahedral Framework Nucleic Acid Probes and a Long-Range SERS Substrate.

Indirect surface-enhanced Raman scattering (SERS)-based methods are highly efficient in detecting and quantitatively analyzing trace antibiotics in complex samples. However, the poor reproducibility of indirect SERS assays caused by the diffusion and orientation changes of the probing molecules on SERS substrates still presents a significant challenge. To address this issue, this study reports the construction of a novel SERS sensing platform using tetrahedral framework nucleic acid (tFNA) as SERS probes in conjunction with a long-range SERS (LR-SERS) substrate. The tFNA was modified with sulfhydryl groups at three vertices and appended with a probing DNA at the remaining vertex, anchored on the substrate surface with a well-ordered orientation and stable coverage density, resulting in highly reproducible SERS signals. Owing to the weak SERS signal of tFNA inherited from its size being larger than the effective range of the enhancing electric field (E-field) of conventional SERS substrates, we utilized an LR-SERS substrate to enhance the signal of tFNA probes by capitalizing on its extended E-field. Correspondingly, the LR-SERS substrate demonstrated a 54-fold increase in the intensity of tFNA probes compared to the conventional substrate. Using this novel platform, we achieved a highly reliable detection of the antibiotic ampicillin with a wide linear range (10 fM to 1 nM), low detection limit (3.1 fM), small relative standard deviation (3.12%), and yielded quantitative recoveries of 97-102% for ampicillin in water, milk, and human serum samples. These findings, therefore, effectively demonstrate the achievement of highly reliable SERS detection of antibiotics using framework nucleic acids and an LR-SERS substrate.

Volumetric absorptive microsampling coupled with hybridization LC-MS/MS for quantitation of antisense oligonucleotides.

Background: Volumetric absorptive microsampling has emerged as a less invasive alternative to venous sampling for small-molecule pharmacokineticstudies, but its application to novel therapeutics such as antisense oligonucleotides (ASOs) is not well-established. Results: A workflow was developed using Mitra microsampling coupled with hybridization LC-MS/MS for accurate determination of fomivirsen, a 21-mer ASO, in human blood. Quantitative recovery was achieved regardless of blood hematocrit level or microsample age by implementingimpact-assisted extraction. A thorough method evaluation confirmed sensitivity, linearity, precision/accuracy, matrix effect, metabolite interference and four months of microsample stability. Conclusion: The combined impact-assisted extraction and hybridization LC-MS/MS workflow demonstrated the successful quantitation of fomivirsen, establishing the validity and applicability of the approach for ASO drug candidates.

Combination of homogeneous liquid–liquid extraction and vortex assisted dispersive liquid–liquid microextraction for the extraction and analysis of ochratoxin A in dried fruit samples: Central composite design optimization

This paper presents a new analytical procedure based on combination of homogeneous liquid–liquid extraction (HLLE) and vortex-assisted dispersive liquid–liquid microextraction (VA-DLLME) for the accurate and reliable determination of ochratoxin A (OTA) in dried fruit samples. To enable selective extraction of the OTA, six hydrophobic deep eutectic solvents (hDESs) were prepared and tested as extraction solvents. Optimization of DES volume, pH, NaCl amount, and mixing time affecting the efficiency of VA-DES-DLLME step was achieved by central composite design (CCD). Using optimized conditions, the working range was obtained in the range 0.4–350 ng mL−1 with an enrichment factor of 138. The limit of detection was 0.12 ng mL−1. To evaluate the accuracy of the method, the samples were analyzed with both the HLLE-VA-DES-DLLME procedure and reference method. The precision of the method was investigated by intraday/interday studies. The robustness of the method was also evaluated by making minor changes to the optimized conditions. The HLLE-VA-DES-DLLME procedure was successfully applied to dried fruit samples and quantitative recoveries were obtained (92.1–99.2%) confirming its usefulness for implementation in routine analysis of food samples.

Engaging Precision Phenotyping to Scrutinize Vegetative Drought Tolerance and Recovery in Chickpea Plant Genetic Resources.

Precise and high-throughput phenotyping (HTP) of vegetative drought tolerance in chickpea plant genetic resources (PGR) would enable improved screening for genotypes with low relative loss of biomass formation and reliable physiological performance. It could also provide a basis to further decipher the quantitative trait drought tolerance and recovery and gain a better understanding of the underlying mechanisms. In the context of climate change and novel nutritional trends, legumes and chickpea in particular are becoming increasingly important because of their high protein content and adaptation to low-input conditions. The PGR of legumes represent a valuable source of genetic diversity that can be used for breeding. However, the limited use of germplasm is partly due to a lack of available characterization data. The development of HTP systems offers a perspective for the analysis of dynamic plant traits such as abiotic stress tolerance and can support the identification of suitable genetic resources with a potential breeding value. Sixty chickpea accessions were evaluated on an HTP system under contrasting water regimes to precisely evaluate growth, physiological traits, and recovery under optimal conditions in comparison to drought stress at the vegetative stage. In addition to traits such as Estimated Biovolume (EB), Plant Height (PH), and several color-related traits over more than forty days, photosynthesis was examined by chlorophyll fluorescence measurements on relevant days prior to, during, and after drought stress. With high data quality, a wide phenotypic diversity for adaptation, tolerance, and recovery to drought was recorded in the chickpea PGR panel. In addition to a loss of EB between 72% and 82% after 21 days of drought, photosynthetic capacity decreased by 16-28%. Color-related traits can be used as indicators of different drought stress stages, as they show the progression of stress.

Magnetic Luffa@metal-organic frameworks (MOF-199) nanocomposite for the solid phase microextraction of some metal ions at trace levels from food and water samples

A new adsorbent (magnetic Luffa@MOF-199) was synthesized and used for magnetic solid phase microextraction for separation–preconcentration of Ni(II), Pb(II), Cr(III), and Cd(II) as 2-nitroso-2-naphthol chelates prior to their flame atomic absorption spectrometer (FAAS) detection. Analytical parameters that affect the quantitative recoveries of analytes such as pH, adsorbent amount, sample and eluent volumes, adsorption and desorption time, and eluent type were optimized. The impact of foreign ions was investigated. The limits of quantification (LOQ) values were 0.35 μg L-1 for Ni(II), 0.38 μg L-1 for Pb(II), 0.55 μg L1- for Cr(III) and 0.12 μg L-1 for Cd(II). The relative standard deviations (RSD) were in the range of 3.4 – 6.0%. The developed method was validated using certified reference materials (CRMs) (TMDA-64.3 fortified water, GBW07424 (GSS-10) soil and 1573a Tomato Leaves). The method was applied to determination of Ni(II), Pb(II), Cr(III), and Cd(II) contents of some food, tobacco, and wastewater samples.

Closed-loop Recycling of Vinylogous Urethane Vitrimers.

Devising energy-efficient strategies for the depolymerization of plastics and the recovery of their structural components in high yield and purity is key to a circular plastics economy. Here, we report a case study in which we demonstrate that vinylogous urethane (VU) vitrimers synthesized from bis-polyethylene glycol acetoacetates (aPEG) and tris(2-aminoethyl)amine can be degraded by water at moderate temperature with almost quantitative recovery (~98%) of aPEG. The rate of depolymerization can be controlled by the temperature, amount of water, molecular weight of aPEG, and composition of the starting material. These last two parameters also allow one to tailor the mechanical properties of the final materials, and this was used to access soft, tough, and brittle vitrimers, respectively. The straightforward preparation and depolymerization of the aPEG-based VU vitrimers are interesting elements for the design of polymer materials with enhanced closed-loop recycling characteristics.

Closed‐Loop Recycling of Vinylogous Urethane Vitrimers

AbstractDevising energy‐efficient strategies for the depolymerization of plastics and the recovery of their structural components in high yield and purity is key to a circular plastics economy. Here, we report a case study in which we demonstrate that vinylogous urethane (VU) vitrimers synthesized from bis‐polyethylene glycol acetoacetates (aPEG) and tris(2‐aminoethyl)amine can be degraded by water at moderate temperature with almost quantitative recovery (≈98 %) of aPEG. The rate of depolymerization can be controlled by the temperature, amount of water, molecular weight of aPEG, and composition of the starting material. These last two parameters also allow one to tailor the mechanical properties of the final materials, and this was used to access soft, tough, and brittle vitrimers, respectively. The straightforward preparation and depolymerization of the aPEG‐based VU vitrimers are interesting elements for the design of polymer materials with enhanced closed‐loop recycling characteristics.

Lipase‐mediated plant oil hydrolysis—Toward a quantitative glycerol recovery for the synthesis of pure allyl alcohol and acrylonitrile

AbstractPlant based triacylglycerides are a sustainable feedstock for the chemical, bioenergy, food and cosmetic sector. While fatty acids conversion has been intensively studied, processes for glycerol valorization have been scarce. In contrast to chemical hydrolysis of plant triacylglycerides enzymatic hydrolysis methods provide a cleaner glycerol stream. This study focuses on the selection of a commercial lipase capable of quantitative hydrolysis of rapeseed‐ and high oleic sunflower oils. Enzymatic process using only water as the reaction medium allows simplified recovery of pure glycerol. Among the six commercial lipase preparations tested, Candida rugosa lipase was identified as the most effective biocatalyst. Catalytic behavior in buffer and pure water was equivalent. Glycerol generated using a washed lipase was recovered by just three purification steps. The FTIR spectrum of the recovered glycerol was equivalent to pure glycerol standard. Over the entire recovery process, 82%–88% of the theoretical glycerol yield could be obtained. Purified glycerol was further didehydroxylated to allyl alcohol by a formic acid mediated open distillation process. The enriched allyl alcohol had a quality, which allows to use it for the synthesis of bio‐based acrylonitrile.

A method of recovering the very low concentration of pathogens in river water by combining centrifugation and membrane filtration

Waterborne pathogens present major public health concerns because of the associated high mortality, morbidity and cost of treatment. Consumption of and contact with water contaminated by faeces is a significant risk factor for transmitting these organisms to humans. Their detection in a water sample is critical to ascertain potential risks to humans. They are relatively low in concentrations in surface waters, making their detection a challenge. Campylobacter is targeted here because it is one of the leading causes of enteric diseases globally, and consensus on the superiority of centrifugation over filtration, and vice versa, to recover Campylobacter spp. from river water samples for detection, has yet to be. Therefore, for this study river water sample was processed by combining both methods in a single set-up to concentrate Campylobacter spp. cells from water samples. This method of combining centrifugation and filtration can be expanded to other bacterial waterborne pathogens of public health importance.•Concentrating cells by centrifugation (14,000 × g for 30 min) to collect the pellets, followed by membrane filtration (using 0.45 µm) of the supernatant to trap any remaining suspended cells, and then pooling both pellet and residue presents an effective method for obtaining a satisfactory quantitative recovery of waterborne pathogens, such as Campylobacter spp. from environmental waters.•This is a critical need for quantitative microbial risk assessment studies.

A Review of Opportunities and Methods for Recovery of Rhodium from Spent Nuclear Fuel during Reprocessing

Rhodium is one of the scarcest, most valuable, and useful platinum group metals, a strategically important material relied on heavily by automotive and electronics industries. The limited finite natural sources of Rh and exponentially increasing demands on these supplies mean that new sources are being sought to stabilise supplies and prices. Spent nuclear fuel (SNF) contains a significant quantity of Rh, though methods to recover this are purely conceptual at this point, due to the differing chemistry between SNF reprocessing and the methods used to recycle natural Rh. During SNF reprocessing, Rh partitions between aqueous nitric acid streams, where its speciation is complex, and insoluble fission product waste streams. Various techniques have been investigated for Rh recovery during SNF reprocessing for over 50 years, including solvent extraction, ion exchange, precipitation, and electrochemical methods, with tuneable approaches such as impregnated composites and ionic liquids receiving the most attention recently, assisted by more the comprehensive understanding of Rh speciation in nitric acid developed recently. The quantitative recovery of Rh within the SNF reprocessing ecosystem has remained elusive thus far, and as such, this review discusses the recent developments within the field, and strategies that could be applied to maximise the recovery of Rh from SNF.