Absorption Spectroscopy Techniques Research Articles

Toluidine Blue for the Determination of Binding of Anionic Polysaccharides to Lipid Raft Domains by Absorption Spectroscopy

The complexes of negatively charged polysaccharides with lipid vesicles have been shown to have applications in medicine, bioremediation, water purification, and construction of nano-biosensors. This article presents research on the formation of these complexes based on the interactions between three types of liposomes, DOPC liposomes (which contain a lipid bilayer in the liquid-disordered (Ld) state), RAFT liposomes (which contain liquid-ordered (Lo) lipid raft domains surrounded by lipids in the Ld state) and SPH–CHL liposomes (which contain a lipid bilayer in the Lo state), and two selected anionic polysaccharides, polysialic acid (PSA) and polygalacturonic acid (PGA). The analysis was conducted using a toluidine blue (TB) probe and the absorption spectroscopy technique. In contrast to DOPC and SPH–CHL liposomes, binding of negatively charged PSA or PGA chains to RAFT liposomes induced a TB absorption maximum shift from 630 nm to 560 nm. The obtained results indicate that toluidine blue can be applied for monitoring the formation of these nano-complexes, and that the boundaries between Ld/Lo domains within membranes in RAFT liposomes can significantly enhance the binding affinity of negatively charged polysaccharides to the lipid bilayer surface. The observed metachromatic shift in TB absorption suggests that negatively charged PSA and PGA chains interact with the Ld/Lo boundaries within RAFT liposome membranes.

Atomic absorption spectrophotometric analysis of toxic and essential heavy metals in some Pakistani medicinal and nutritional herbs along with their health risk assessment upon human consumption

Context: Medicinal herbs have gained worldwide popularity as natural raw materials, not only for herbal formulations and nutraceuticals but also in pharmaceutical and cosmeceutical products, while food and culinary products are available for the general population, having great benefits. However, heavy metal contamination in medicinal herbs is a dreadful health issue in the current scenario due to ever-increasing levels of environmental pollution and malagriculture practices. Aims: To investigate the existence of some metal impurities, either toxic (Pb, Hg, Cd) or essential (Ni, and Cu), along with their concentration in thirteen selected medicinal herbs that are generally utilized in Pakistan as food and medicine. Methods: The wet acid digestion method was employed for the atomic absorption spectroscopic technique to determine heavy metal contents. The system was calibrated first by preparing a standard solution for each metal in various concentrations, and then the samples were validated. Results: Different concentrations of particular metal impurities were obtained in different herbs ranging from 0.98¬-2.39, 2.25-3.75, 0.42-1.17, 0.87-2.39, and 2.03-4.96 ppm for lead (Pb), mercury (Hg), cadmium (Cd), nickel (Ni), and copper (Cu), respectively. Moreover, the severity of health risk was assessed by calculating the estimated daily intake, targeted hazard quotient, target cancer risk and hazard index, which were found to be less than 1 value. Conclusions: This study revealed that all medicinal and nutritional herbs are almost within limits according to USP and USEPA, but the regular monitoring of heavy metals in edible herbs and the implementation of mitigation procedures can help in the control and prevention of adverse health consequences in the human population.

Red edge effect of chalcone derivatives and their application in Bio-sensing.

A series of chalcone-based compounds with varied functional groups were designed and synthesized through green chemistry. Polarity-tuned solvatochromic photophysical studies were thoroughly performed using steady-state absorption and emission spectroscopic techniques. These donor-acceptor structured chalcones were capable of exhibiting excitation dependent fluorescence (EDF), which is widely known as the red edge effect, with a large Stokes shift above 140 nm, making them capable of accessing the yellow to blue region of the spectrum. Furthermore, the ease of tuning the fluorescence property was utilized in the field of biosensors to obtain tunable brilliant blue to green colors for the first time. Computational studies indicated the presence of relatively compact states, which might be one of the key factors responsible for the red edge effect.

Four-channel silicon nitride wavelength beam combiners for multi-gas absorption spectroscopy.

The detection and measurement of multiple trace gases based on the laser absorption spectroscopy technique requires laser sources with wavelength tunability in multiple wave bands. In this Letter, we present an on-chip wavelength beam combiner based on silicon nitride Mach-Zehnder interferometers (MZIs) and a modified multimode interferometer (MMI) structure to multiplex light with different wavelength spacings. An MZI composed of a standard 1 × 2 MMI and 2 × 2 MMI is employed to digitally multiplex two wavelengths within ∼100 nm spacing. The two wave bands with a spacing of a few hundred nanometers are multiplexed by a compact modified MMI structure. The measured insertion losses of all four channels are around 2.5 dB from the 1650 nm wave band to the 2050 nm wave band. A tunable diode laser absorption spectroscopy (TDLAS) measurement of multi-gas is demonstrated using the device as the wavelength beam combiner.

Photophysics of 5,6,7,8-tetrahydrobiopterin on a femtosecond time-scale.

Photophysics of 5,6,7,8-tetrahydrobiopterin on a femtosecond time-scale.

Optical Sensing System Based on Bidirectional Self-Correction Technology: An Online Detection Method for Carbon Disulfide and Sulfur Dioxide in Gas-Insulated Switchgear.

Carbon disulfide (CS2) and sulfur dioxide (SO2) are typical indicative gases for the early warning and diagnosis of faults in gas-insulated switchgear. In this study, an optical sensing system is reported for online detection of CS2 and SO2 based on a bidirectional self-correction technology (BSCT). First, the differential absorption signals of CS2 and SO2 in the wavelength range of 195-230 nm are obtained using the UV differential optical absorption spectroscopy (UV-DOAS) technique. On this basis, a BSCT is proposed to decouple the spectral lines that exhibit significant overlap. This method primarily employs bidirectional difference spectroscopy to mutually correct the spectra of CS2 and SO2, combined with spectral reconstruction to extract the single-component absorption signals of CS2 and SO2 from the mixed gas spectra. Furthermore, the effectiveness of this novel decoupling technique is validated by comparing the decoupling results with the absorption spectra of single-component standard gases at corresponding concentrations. Finally, the quantitative relationships between the concentrations of target gases (CS2, SO2) and the optical parameters are modeled using the least-squares method. The experimental results show that the mean absolute percentage errors of CS2 (19.00-3735.35 ppb) and SO2 (0.19-38.77 ppm) are 0.543 and 0.521%, respectively. At an effective optical range of 50 cm, the system achieves the lowest detection limits of 0.5 ppb for CS2 and 12 ppb for SO2, representing the best results reported to date for the online detection of CS2 and SO2 in the ppb-ppm range.

Critical Role of Carrier Cooling Mechanism in WS2/CsPbBr3 Hybrid Nanocomposites for Enhanced Photodetector Performances.

Heterostructures and nanocomposites comprising transition metal dichalcogenides (TMDCs) and halide perovskite nanocrystals (NCs) are prominently used in several optoelectronic devices. Hot carriers (HCs) are the charge carriers possessing higher kinetic energy than surrounded thermal distributions. Properly utilizing these HCs by slowing down their cooling mechanism reduces the energy losses in optoelectronic devices. Herein, employing the femtosecond transient absorption spectroscopy (fs-TAS) technique, the slowdown processes of HC relaxations are reported in WS2/CsPbBr3 hybrid-nanocomposites due to the hot-phonon bottleneck. HCs relaxation time increases from ≈6ps in CsPbBr3 NCs to ≈10ps in WS2/CsPbBr3 nanocomposites at an excitation fluence of 17.7µJcm-2. The maximum HCs temperature TC increased to 1181 K in WS2/CsPbBr3 nanocomposites with an observed TC of 856 K in pristine NCs. The electron transfer process from NCs to WS2 nanosheets has been observed in these nanocomposites with time component t2 ≈38.0-102.4 ps in pristine NCs and 20.9-66.9ps in nanocomposites, became faster at excitation-fluence of 17.7-99.8µJcm-2. Furthermore, a significant enhancement in nanocomposite-based photodetector confirmed the efficient charge transfer at the heterojunction, resulting ≈400%, ≈420%, and ≈200% increase in the photocurrent, responsivity, and detectivity, respectively, compared to the pristine devices.

Degradation of Glyphosate to Benign N‐Formyl Glycine Using MOF‐808 Nanocrystals

AbstractGlyphosate (N‐phosphonomethyl glycine, GPh) is an industrial herbicide used worldwide in modern agricultural practices. With the growing concerns regarding cumulative environmental and health effects, pathways for catalytic GPh degradation to benign products are becoming a pressing societal need. This report demonstrates that Zr‐based metal–organic framework (MOF‐808) with different crystal sizes and designed defect sites can be employed as an efficient heterogeneous catalyst for the complete degradation of GPh at room temperature. Importantly, the degradation mechanism produces N‐formyl glycine and hydroxymethyl‐phosphonate, which are largely innocuous chemicals, especially when compared to more common GPh degradation products. Nanocrystalline MOF‐808 (nMOF‐808) exhibits enhanced reactivity than larger MOF‐808 crystals, attributed to the higher coordination of hydroxyl and water molecules to the secondary building units (SBU) as determined using a range of X‐ray absorption spectroscopy (XAS) techniques. These studies indicate that the crystal size‐dependency in GPh degradation is related to structural modifications on coordinative unsaturated Zr site that promote the fast exchange of weakly bonded ligands. Taken together, this study demonstrates that GPh degradation can be optimized through ligand field tuning in MOFs, which can help improve overall reactivity while also pushing the reaction toward desirable, nontoxic products.

Degradation of Glyphosate to Benign N-Formyl Glycine Using MOF-808 Nanocrystals.

Glyphosate (N-phosphonomethyl glycine, GPh) is an industrial herbicide used worldwide in modern agricultural practices. With the growing concerns regarding cumulative environmental and health effects, pathways for catalytic GPh degradation to benign products are becoming a pressing societal need. This report demonstrates that Zr-based metal-organic framework (MOF-808) with different crystal sizes and designed defect sites can be employed as an efficient heterogeneous catalyst for the complete degradation of GPh at room temperature. Importantly, the degradation mechanism produces N-formyl glycine and hydroxymethyl-phosphonate, which are largely innocuous chemicals, especially when compared to more common GPh degradation products. Nanocrystalline MOF-808 (nMOF-808) exhibits enhanced reactivity than larger MOF-808 crystals, attributed to the higher coordination of hydroxyl and water molecules to the secondary building units (SBU) as determined using a range of X-ray absorption spectroscopy (XAS) techniques. These studies indicate that the crystal size-dependency in GPh degradation is related to structural modifications on coordinative unsaturated Zr site that promote the fast exchange of weakly bonded ligands. Taken together, this study demonstrates that GPh degradation can be optimized through ligand field tuning in MOFs, which can help improve overall reactivity while also pushing the reaction toward desirable, nontoxic products.

Investigation of carcinogenic and non-carcinogenic human health risk of heavy metals in spent synthetic-based drilling mud

This study conducted a broad risk assessment of the heavy metals present in spent synthetic- based drilling mud in the Niger Delta, Nigeria, particularly on evaluating their carcinogenic and non-carcinogenic effects on human health. Five samples drawn from five oil fields in the region were analyzed for their concentrations of heavy metals by the technique of atomic absorption spectroscopy. The results indicated that the concentration of majority of the heavy metals in the studied muds surpassed the permissible limits for disposal of the metals. Observed concentrations of the different heavy metals were used to calculate the health risk in children and as well as adults. While the Hazard Index (HI) for adults for various pathways was 0.26, indicating that non-carcinogenic effects of the metals in grownups were negligible, the non-carcinogenic effects in children habiting the oil producing villages showed to be severe as shown by the HI of 2.24- a value > 1. The same argument holds for progenies dwelling in areas where untreated spent drilling muds are disposed. 9.13E-05 and 5.29E-05, calculated as carcinogenic risk values for children and adults, respectively are within the permissible limits (1.00E-06 to 1.00E-04). While the results suggest for protective measures against non-carcinogenic effects to be provided for children exposed to used drilling mud, the study showed no evidence to support significant long-term cancer-related health concerns in either group.

Dual exsolution in silver‐functionalized layered and cubic perovskite oxides

AbstractIn this work, exsolution is achieved from both the A‐site and B‐site of (BaGd0.8La0.2)1‐xAgxCo2O6‐δ and (BaLa)1‐xAgxCoFeO6‐δ (x = 0.04, 0.1, and 0.2) perovskites prepared via solid‐state sintering. Through synchrotron radiation powder X‐ray diffraction and X‐ray absorption spectroscopy techniques, the chemical composition of the nanoparticles was determined to constitute both Ag and CoO. Microstructural studies were done using scanning electron microscopy with varying sizes and shapes of nanoparticles present for respective annealing atmospheres and temperatures. By applying a numerical model to experimental data, it was also established that the changes in enthalpy for oxygen vacancy formation decrease with an increase in silver dopant. From thermogravimetric measurements, the single (BaLa)0.95Ag0.10CoFeO6‐δ perovskite had relatively higher water uptake than the layered (BaGd0.8La0.2)0.95Ag0.10Co2O6‐δ perovskite. The total electrical conductivity done in dry and wet conditions decreased with an increase in temperature in the range of 300–800°C for both layered and single perovskites. The results obtained from electrical conductivity relaxation measurements of (BaGd0.8La0.2)0.95Ag0.10Co2O6‐δ with nanoparticles exhibit increased oxygen reduction reaction activity than (BaLa)0.95Ag0.10CoFeO6‐δ with nanoparticles.

A Non-invasive Lung Disease Study of Exhaled Breath Nitric Oxide Based on Ultraviolet Differential Absorption Spectroscopy Techniques.

In this study, a non-invasive device based on ultraviolet differential absorption spectroscopy (UV-DOAS) technology for detecting fractional exhaled nitric oxide (FeNO)was developed and clinically validated in patients with various lung diseases. The diagnostic potential of FeNO was explored by analysing subgroups of patients with lung cancer, nodules, and other disease. The results showed that FeNO concentrations were significantly higher in patients with malignant tumours than in healthy controls (p < 0.01). The diagnostic efficacy of FeNO in different lung diseases was confirmed by ROC analysis: the AUC values were 0.925 for malignant tumours, 0.925 for suspected malignant/benign tumours, 0.792 for benign lesions, and 0.938 for infectious/inflammatory diseases. The significant postoperative FeNO level decrease supports the diagnostic use of FeNO in different stages of the disease. Compared with conventional electrochemical, chemiluminescent and fluorescent probe methods, the UV-DOAS technique has significant advantages regarding sensitivity and portability, suggesting its potential for clinical application.

Ultrasensitive and Fast Gas Detection Based on Room‐Temperature Indium Arsenide Mid‐Wavelength Infrared Photodetectors

AbstractCombustible hydrocarbon gases, typified by methane, are invisible, odorless, and imperceptible, yet they pose significant hazards to human safety and the environment. Therefore, monitoring these gases is crucial in managing and mitigating potential hazards. Here, a gas sensing system is proposed based on the non‐dispersive infrared absorption spectroscopy (NDIR) technique. Its core component is a home‐built indium arsenide (InAs) semiconductor mid‐wavelength infrared photodetector. By material growth and device structure optimization (a peculiar potential barrier layer is designed to form a heterojunction and suppress diffusion carriers), the InAs‐based photodetectors show a low‐noise performance of 1.62 × 10−12 A·Hz−1/2 and a record high room‐temperature detectivity of 2.1 × 1010 cm·Hz1/2·W−1 with superior response speed of &lt;40 ns. The sensing system, therefore, gains an ultra‐sensitive (&lt;1 ppm) and fast (≈350 ms) gas detection capability of methane compared to current NDIR equipment. The method used in this study paves an avenue for designing ultrasensitive NDIR systems based on photovoltaic devices and provides a new paradigm for highly integrated gas sensing hardware.

Mid-infrared absorption spectroscopy for in-situ and spatially resolved measurements of nitric oxide in premixed ammonia-methane co-fired flames.

Laser absorption spectroscopy (LAS) is a well-established measurement technique for quantitative chemical speciation in a combustion environment. However, in-situ LAS measurement of nitric oxide (NO) in ammonia flames has never been reported in the literature. This is despite the community's recent strong interest in carbon-neutral ammonia combustion and the associated NO formation problem. In this work, we demonstrate the development and validation of a mid-infrared laser absorption sensor for in-situ measurements of NO formation and evolution in premixed ammonia and ammonia-methane cofired flames. To achieve calibration-free and interference-free measurements, the sensor exploits the NO absorption feature near 1900.07 cm-1 using the techniques of both direct absorption spectroscopy and wavelength modulation spectroscopy. Special efforts were given to address the thermochemical non-uniformity along the light path which was shown to have notable effects on measurement accuracy. Detailed computational fluid dynamics modeling on the flame structure was performed along with theoretical spectral simulation to assist in the treatment of the non-uniformity effects. Comprehensive measurements were then performed in flames with different ammonia proportions and equivalence ratios, with results compared to data from probe sampling methods and kinetic modeling. The present work is the first demonstration of an in-situ mid-infrared LAS sensor for quantitative and spatially resolved NO measurement in ammonia flames.

Determination of Desferrioxamine in the Drug Desferal™ as DFOM-Au (III) Complex by Using Indirect Electrothermal Atomic Absorption Spectrometry and Other Techniques.

استحدث طريقة تحليلية غير مباشرة لتعيين المادة الفعالة الدسفيروكسامين في دواء الدسفرال من خلال تفاعل هذا المركب مع عنصر الذهب الثلاثي لتكون معقد مخلبي يجري استخلاصه بمذيب رابع كلوريد الكربون وحقن حجم معيين من هذا المستخلص في الفرن الغرافيتي المطلي بكربيد الزركونيوم . جرى دراسة معرفة تكوين وتركيب المعقد DFOM-Au(III)) بالتقنيات المعروفة مثل مطيافية الاشعة تحت الحمراء ومطيافية الاشعة الفوبنفسجية-المرئية وتبين ان النسبة المولية للعضيدة-الفلز هي 1:1. لقد تم دراسة العوامل التجربية التي تؤثر على تكوين هذا المعقد من خلال حساب الممتصية الذرية بالفرن الكرافيتي للحصول على الظروف الامثلية . كما تم تثبيت ارقام الاستحقاق التحليلية (figures of merits ) من منحنيات المعايرة كالمدى الخطي والحساسية وحد الكشف ونسبة الاسترداد بالمائة والدقة المعبر عنها بالاستنساخيه . جرى تطبيق هذه الطريقة لتعيين الدسفيروكسامين في دواء الدسفرال ووجد ان تركيزه هو 488 و 484 ملغم / وحدة في هذا الدواء باستعمال المعايرة المباشرة واضافات القياس على التوالي مقارنة بالكمية المصرحة على العبوة وهي 500 ملغم / وحدة . كانت نتائج مطيافية الامتصاص الذري غير المباشرة ومطيافية الاشعة الفوق البنفسجية-المرئية المباشرة متفقة إذ نفذت معظم الحسابات الاحصائية باستخدام البرنامج الحاسوبي (Minitab version 11) .

A Complete Description of the Ultrafast Proton Transfer Dynamics in the Excited State of D-Luciferin.

Excited-state proton transfer (ESPT) in organic photoacids is a widely studied phenomenon in which D-luciferin is of special mention, considering the fact that apart from its phenolic OH group, the nitrogen atoms at either of the two thiazole moieties could also participate in hydrogen bonding interactions with a proton-donating solvent during ESPT. As a result, several transient species could appear during the ESPT process. We hereby deploy subpicosecond time-resolved fluorescence upconversion (FLUP) and transient absorption (TA) spectroscopic techniques to understand the detailed photophysics of D-luciferin in water as well as in dimethyl sulfoxide (DMSO) and ethanol. These transient-state spectroscopic studies reveal the population of two kinds of hydrogen-bonded (HB) complexes (HBCs) in the excited singlet (S1) state─HBC-I, which is formed at the OH site of the hydroxy benzothiazole moiety with a proton-accepting solvent, and the other one is HBC-II, which is formed at the N atom site of the thiazoline moiety with a proton-donating solvent. This study provides a complete description of the mechanism of the deprotonation process in HBC-I through distinct identification and characterization of the spectroscopic properties and temporal dynamics of those transient species associated with the four stages of the ESPT process as proposed by the Eigen-Weller model. This study also identifies and characterizes HBC-II, which, however, does not participate in the deprotonation process but provides an efficient nonradiative relaxation mechanism via geminate proton recombination.

Application of Marine Algae for Bio-tanning System

Sea weeds are plant-like organisms which are commonly grown in coastal regions. These materials are explored for different industrial applications such as food, cosmetics, chemicals, paint, pharmaceutical, etc. Several studies have been reported on the antimicrobial and antioxidant properties of various seaweed. However, utilization of seaweed for stabilization of collagen has been less explored. Recovery and reuse of collagen from tannery waste was found to be more prominent in the waste to wealth mission of the leather industry. Bio-crosslinkers from marine waste would be a new avenue for collagen stabilization. In the present research, phlorotannin, has been extracted and characterized for its tanning ability. Extracted phlorotannin was interacted with collagen at different hierarchical organizations (collagen solution, rat tail tendon and skin) to understand the interaction efficacy. Phlorotannin interacted collagen samples have been physico-chemically characterized through absorption and vibrational spectroscopic techniques. From these experimental studies, it has been found that extracted phlorotannin can act as a potential stabilizing agent, which enhances thermal resistance of the skin matrix. Phlorotannin substantially influences collagen aggregation, by enhancing the rate of aggregation without affecting the architectural ordering of collagen. This study implicates the waste utilization from coastal areas for stabilization of collagen, which is a by-product of meat industry.

Evaluation of the Arrhenius behavior of n-dodecane radical cation (RH˙+) reactivity with lanthanide ion-complexed N,N,N',N'-tetraoctyl diglycolamide (TODGA).

Temperature-dependent rate constants for the reaction of the n-dodecane radical cation (RH˙+) with trivalent lanthanide ion-complexed N,N,N',N'-tetraoctyl diglycolamide (TODGA) over the range 10-40 °C have been determined using electron pulse radiolysis/transient absorption spectroscopy techniques. For the free ligand, an activation energy of Ea = 20.4 ± 0.7 kJ mol-1 and pre-exponential factor of ln(A) = 31.23 ± 0.27 were obtained, corresponding to a room-temperature rate constant of k = (9.94 ± 0.52) × 109 M-1 s-1. The RH˙+ reactivity with La(TODGA)3(NO3)3, Nd(TODGA)3(NO3)3, Gd(TODGA)3(NO3)3, Yb(TODGA)3(NO3)3 and Lu(TODGA)3(NO3)3 complexes had rate constants of k = (5.30 ± 0.51) × 1010, (4.23 ± 0.18) × 1010, (2.44 ± 0.13) × 1010, (1.68 ± 0.03) × 1010, and (9.1 ± 0.7) × 109 M-1 s-1, respectively. The corresponding Arrhenius activation energies determined for three (La, Gd, Lu) lanthanide-TODGA complexes showed consistent values of Ea = 35 ± 2.2, 35.3 ± 2.0, and 33.5 ± 3.9 kJ mol-1, respectively. The similar and relatively large barrier energy suggests a common reaction mechanism involving electron abstraction from one of the coordinating nitrate anions, which is consistent with previously reported decreased degradation of TODGA complexes under radiolytic environments.

Luminescent Oxygen Sensor with Self-Sterilization Properties Based on Platinum(II)octaethylporphyrin in Polymeric Nanofibers.

Optical sensors based on the quenching of the luminescence of platinum(II)octaethylporphyrin (PtOEP) encapsulated in nanofiber polymeric membranes were prepared by electrospinning. The samples were characterized using scanning electron microscopy, confocal luminescence microscopy, absorption spectroscopy, and steady-state and time-resolved luminescence techniques. The properties of the sensors were changed by the selection of different polymeric membranes using polycaprolactone, polystyrene, polyurethane Tecophilic, and poly(vinylidene fluoride-co-hexafluoropropylene) polymers. Among them, biodegradable and biocompatible sensors prepared from polycaprolactone with a high oxygen diffusion coefficient exhibited a fast response time (0.37 s), recovery time (0.58 s), high sensitivity (maximum I 0 /I ratio = 52), reversible luminescent response, and linear Stern-Volmer quenching over the whole range of oxygen contents in both the gas atmosphere and aqueous media. Moreover, the proposed sensors exhibited high antibacterial properties, resulting in self-sterilization character of the membrane surface due to the photogeneration of singlet oxygen. This dual character can find application in the biomedical field, where both properties (oxygen sensing and self-sterilization) can be acquired from the same material.

Toward a Machine Learning Approach to Interpreting X-ray Spectra of Trace Impurities by Converting XANES to EXAFS.

The fact that the photoabsorption spectrum of a material contains information about the atomic structure, commonly understood in terms of multiple scattering theory, is the basis of the popular extended X-ray absorption spectroscopy (EXAFS) technique. How much of the same structural information is present in other complementary spectroscopic signals is not obvious. Here we use a machine learning approach to demonstrate that within theoretical models that accurately predict the EXAFS signal, the extended near-edge region does indeed contain the EXAFS-accessible structural information. We do this by exhibiting deep operator neural networks (DeepONets) that have learned the relationship between the extended and near edge portions of the X-ray absorption spectrum to predict the former from the latter. We find that we can accurately predict the EXAFS spectrum between 6 and 14 Å-1 from the first 6 Å-1 (≈100 eV) of the absorption spectrum of Cu2+ substitutional defects in the Fe3+ mineral hematite (α-Fe2O3). This surprising finding implies that theoretical analyses of X-ray absorption spectra could be implemented that extract the same conclusions as high-quality EXAFS studies from spectra collected over a much smaller range of photon energies. This relaxes a host of experimental limitations related to the X-ray source and measurement sample, including collection time, minimum dopant concentration, source brilliance, and energy range. We describe the theoretical data sets and DeepONet construction and show that the resulting DeepONets produce EXAFS that recovers linear combination fits to experimental data with accuracy approaching the original ab initio calculations. We discuss the implications of our findings for minor constituent characterization and for understanding the information content of spectroscopic data more broadly, including how this approach might be applied to measured experimental spectra. To encourage similar efforts, the simulated X-ray spectra, machine learning, and fitting code are publicly available.