Photodiode Array Research Articles

Cefoperazone Sodium Content Assay in Pharmaceutical Formulations: Development and Validation of High‐Performance Liquid Chromatographic Method

A precise and sensitive RP‐HPLC method is used to assay pharmaceutical dosage forms and bulk drugs for cefoperazone sodium (CPZ). The mobile phase for cefoperazone separation is a combination of acetonitrile and 0.05 M ammonium acetate buffer (pH 4.5) in a 70 : 30 (v/v) ratio. This was separated by using a Waters XTerra RP‐18 column (5 µm 250 × 4.6 mm internal diameter) that was working at a flow rate of 1.0 ml/min. Photodiode array detectors are able to set it at 235 nm. Based on the percentage recovery, the process produced a notable linear response ranging from 0.2 to 20 µg/ml, with a significant precision of 0.27 to 0.67% and an excellent accuracy of 99.90 to 100.02%. Because of its outstanding sensitivity, accuracy, precision, and ease of use, we highly suggest using the reversed‐phase HPLC method. Therefore, a laboratory could utilize this method for routine quality control analysis.

Counterfeiting honey with phosphodiesterase inhibitors for sexual activity enhancement: detection using high-performance liquid chromatography coupled with a photodiode array detector (HPLC-PAD)

Counterfeiting honey with phosphodiesterase inhibitors for sexual activity enhancement: detection using high-performance liquid chromatography coupled with a photodiode array detector (HPLC-PAD)

Developing a highly validated and sensitive HPLC method for simultaneous estimation of cefotaxime and paracetamol in pure and pharmaceutical preparations

An isocratic HPLC technique was exploited and validated for the quick simultaneous separation and measurement of cefotaxime and paracetamol in vials dosage forms, with a total analysis time of 3 minutes. The process of separation was carried out on a Thermo Scientific® Venusil XBPC18 (L) (5µm, 4.6x250 mm) using a mobile phase of ACN: distilled water (70:30, v/v) at the ambient temperature. The flow rate used in the experiment was 1 mL/min, and the highest level of absorption was determined by high-performance liquid chromatography with photodiode array detection (HPLC-PDA) employing a PDA detector set at a wavelength of 255 nm. The established retention times for cefotaxime and paracetamol were 1.79 and 2.97 minutes, respectively, suggesting reduced analysis duration. The observed limits of detection for ceftaxime and paracetamol were 4.2×10-5 and 1.2×10-5 µg/mL, respectively, indicating a significant level of sensitivity in the approach. The approach was subsequently verified in accordance with the requirements set out by the Food and Drug Administration (FDA) for the quantification of medicines in vial dosage form.

Development of an eco-friendly capillary electrophoresis method for the simultaneous determination of piperacillin, tazobactam and ibuprofen in plasma samples: application to a pharmacokinetic study in rats.

Piperacillin (PIP) and tazobactam (TAZ) are broad-spectrum beta-lactam antimicrobial agents, which are frequently co-prescribed in intensive care units (ICUs) worldwide. Ibuprofen (IBU) is a potent pain killer which is commonly co-prescribed with PIP and TAZ postoperatively. The combination therapy of PIP, TAZ, and IBU has been administered commonly after surgical procedures to combat aerobic and anaerobic microbes and exert anti-inflammatory and analgesic effects. This study describes, for the first time, the development of a new capillary electrophoresis (CE) method with a photodiode array detector for the simultaneous determination of PIP, TAZ, and IBU in plasma samples. The experimental factors affecting the elution of analytes were carefully optimized. The final analysis was achieved using a fused silica capillary (58 cm effective length and 75 μm ID) and a background electrolyte solution containing a methanol/borax buffer solution (15 mM and pH 9.3) in a ratio of (10 : 90 v/v) with a driving voltage of 30 kV and detection at 210 nm. The relationship between the peak area and concentration was linear from 1 to 200 μg mL-1 for both PIP and TAZ and from 3 to 200 μg mL-1 for TAZ. The method used was thoroughly validated in accordance with the validation requirements set out by the Food and Drug Administration (FDA) for bio-analytical processes. The proposed CE method was employed to conduct pharmacokinetic and bioavailability studies of the drugs in rat models. The pharmacokinetic results revealed that there is a significant impact upon prescribing this combination concurrently when compared to their single administration. To illustrate, the time required to reach their maximum concentrations (T max) was increased by 0.25 h for both PIP and TAZ, whereas it was increased by 0.5 for IBU. When it comes to their maximum concentration (C max), it was increased by 13.7%, 55.5%, and 44% for PIP, TAZ, and IBU, respectively. Furthermore, the bioavailabilities of PIP, TAZ, and IBU were significantly increased by 55.4%, 19.7%, and 35.6%, respectively. These findings require caution when these drugs are co-prescribed as there is a noticeable augmentation in their therapeutic impacts. Additionally, the greenness of the proposed method was assessed by three metric tools. In conclusion, the method is a valuable tool for further studies on drug-drug interaction in humans.

Acanthus mollis Formulations for Transdermal Delivery: From Hydrogels to Emulsions.

Topical formulations of Acanthus mollis L. leaf and the optimization of the release of their active compounds and their topical bioavailability were investigated for the first time. In vitro, the release of active compounds from three formulations-an oil-in-water cream and two hydrogels (Carbopol 940 and Pluronic F-127)-was determined using Franz diffusion cells. Detection and quantification of the compounds was performed via high-performance liquid chromatography with a photodiode array (HPLC-PDA). DIBOA, a bioactive compound of this medicinal plant, exhibited release kinetics of the Weibull model for the Carbopol and Pluronic F-127 formulation, identifying it as a potential active agent to optimize the topical distribution of the formulations. The implications extend to applications in inflammation treatment and tyrosinase inhibition, suggesting that it can make a significant contribution to addressing skin conditions, including melanoma and various inflammatory diseases.

Phenological Variations in the Content of Polyphenols and Triterpenoids in Epilobium angustifolium Herb Originating from Ukraine.

The composition of secondary metabolites undergoes significant changes in plants depending on the growth phase and the influence of environmental factors. Therefore, it is important to determine the harvesting time of plant material for the optimum secondary metabolite profile and therapeutic activity of the primary material. The shoots of Epilobium angustifolium are used as a healing tea due to the presence of polyphenolic compounds. The aim of this study was to assess the composition of phenolic compounds and triterpenoid saponins in E. angustifolium leaves and flowers and to estimate the dynamics of their content depending on the flowering phase. Qualitative and quantitative characterisation of polyphenols and triterpenoids in E. angustifolium samples from Ukraine of three flowering phases were performed using the high-performance liquid chromatography photo diode array (HPLC-PDA) method. During the present study, 13 polyphenolic compounds and seven triterpenoids were identified in the plant material. It was noted that the largest content and the best polyphenol profile was in late flowering. The most important polyphenolic compounds in the plant material were chlorogenic acid, hyperoside, isoquercitin, and oenothein B. The triterpenoid profile was at its maximum during mass flowering, with corosolic and ursolic acids being the dominant metabolites. The results of the analysis revealed that the quantity of many of the tested metabolites in the raw material of E. angustifolium is dependent on the plant organ and flowering phase. The largest content of most metabolites in the leaves was in late flowering. In the flowers, the quantity of the metabolites studied was more variable, but decreased during mass flowering and increased significantly again in late flowering. The results show that E. angustifolium raw material is a potential source of oenothein B and triterpenoids.

Development and Validation of Reverse-Phase High-Performance Liquid Chromatography Method for Simultaneous Estimation of Doxorubicin and Clotrimazole.

A reverse-phase high-performance liquid chromatographic (RP-HPLC) method was developed to analyze the simultaneous estimation of doxorubicin and clotrimazole. The method was achieved by Nucleodur C18 column with dimension 250 × 4.6 mm (5 μm) using gradient elution. The mobile phase contained 0.2% formic acid (pH 3.2) and acetonitrile. The flow rate was kept at 1.0 mL/min and detection and quantitation of both drugs (doxorubicin and clotrimazole) were achieved using a photodiode array detector at 276 nm, which was the isosbestic point for both drugs. The proposed method was validated according to the current International Council for Harmonization of Technical Requirements of Pharmaceuticals for Human Use guidelines for specificity, linearity, accuracy, precision, and robustness. The developed method showed a linear response (R2 > 0.999), and was accurate (recoveries 97%-103%), precise (resolution ≤1.0%), sensitive, and specific. Thus, the developed RP-HPLC method for the simultaneous estimation of both drugs was successfully validated and can be utilized for the estimation of these drugs in the formulations being developed.

Concurrent Estimation of a Three Combination Type-2 Anti-diabetic Oral Dosage Form by Ultra-performance Liquid Chromatography

Estimation of a three-combination dosage form containing metformin (MET), vildagliptin (VLDG), and remogliflozin etabonate (REMET) was performed by developing an economically simple and isocratic simultaneous method using ultra-performance liquid chromatograph (Alliance 1100 series) comprising of X-Bridge (50 × 4.6 mm, 2.5 μ) C18 column and photo diode array detector. 0.1 % v/v trifluoro acetic acid: acetonitrile (60:40% v/v) movable phase at 0.5 mL/min was used. The analytes were detected at a wavelength of 240.0 nm at 8.0 min. run time. The respective retention times of 1.004, 2.005, 5.118 min. was achieved concurrently for metformin, vildagliptin, and remogliflozin etabonate. The method was validated for various parameters according to international council for harmonization. Linearity was established at 187.50 to 1125.00 μg/mL (R2 = 0.9997), 18.75 to 112.50 μg/mL (R2 = 0.9990), 37.50 - 225.00 μg/ mL (R2 = 0.9997). The respective limit of detection and quantification were 22.50; 75.0 (MET) 2.25; 7.5 (VLDG) and 4.50; 15.0 μg/mL (REM ET). A recovery (% w/w) of 99.0 ± 1 % was obtained for metformin, vildagliptin, and remogliflozin etabonate, respectively. Various degradation studies were conducted and degradants were identified at different retention times.

Low dose indirect conversion X-ray sensors based on Cs3Cu2I5 and CsPbBr3 coated BPW-34 photodiode

Metal halide perovskites (MHPs) have demonstrated tremendous applicability in optoelectronic research owing to their fascinating properties and extensive range of crystal structures. Among the MHPs, cesium copper iodide (Cs3Cu2I5) and cesium lead bromide (CsPbBr3) have been utilized in numerous applications like photovoltaics, photodetectors, and scintillation detectors. In this report, we present a cost-effective approach to developing an indirect conversion X-ray sensor based on Cs3Cu2I5 and CsPbBr3, utilizing a commercial photodiode (BPW 34). The MHPs were synthesized by solid-state exchange reaction, dissolved in dimethyl formamide (DMF), and recrystallized within a polymer matrix. The MHP polymer matrix was then coated onto the top surface of the photodiodes as thick films. The photocurrent characteristics of Cs3Cu2I5 and CsPbBr3 indirect X-ray sensors, upon exposure to X-rays at 70 kVp energy under various X-ray exposures and zero bias conditions, were recorded. Both MHPs exhibited a significant response to the incident X-rays. These outcomes highlight the potential of Cs3Cu2I5 and CsPbBr3 scintillators for fabricating X-ray imagers based on commercial photodiode arrays.

Chemical Analysis of the Antihyperglycemic, and Pancreatic α-Amylase, Lipase, and Intestinal α-Glucosidase Inhibitory Activities of Cannabis sativa L. Seed Extracts.

Cannabis is considered (Cannabis sativa L.) a sacred herb in many countries and is vastly employed in traditional medicine to remedy numerous diseases, such as diabetes. This research investigates the chemical composition of the aqueous extracts from Cannabis sativa L. seeds. Furthermore, the impact of these extracts on pancreatic α-amylase and lipase, and intestinal α-glucosidase enzymes is evaluated, as well as their antihyperglycemic effect. Analysis of the chemical composition of the aqueous extract was conducted using high-performance liquid chromatography with a photodiode array detector (HPLC-DAD). In contrast, the ethanol, hexanic, dichloromethane, and aqueous extract compositions have been established. Additionally, the inhibitory effects of ethanolic, dichloromethane, and aqueous extracts on pancreatic α-amylase and lipase, and intestinal α-glucosidase activities were evaluated in vitro and in vivo. The results of HPLC analysis indicate that the most abundant phenolic compound in the aqueous cannabis seed extract is 3-hydroxycinnamic acid, followed by 4-hydroxybenzoic acid and rutin acid. Moreover, administration of ethanolic and aqueous extracts at a dose of 150 mg/Kg significantly suppressed postprandial hyperglycemia compared to the control group; the ethanolic, dichloromethane, and aqueous extracts significantly inhibit pancreatic α-amylase and lipase, and intestinal α-glucosidase in vitro. The pancreatic α-amylase test exhibited an inhibition with IC50 values of 16.36 ± 1.24 µg/mL, 19.33 ± 1.40 µg/mL, 23.53 ± 1.70 µg/mL, and 17.06 ± 9.91 µg/mL for EAq, EDm, EET, and EHx, respectively. EET has the highest inhibitory capacity for intestinal α-glucosidase activity, with an IC50 of 32.23 ± 3.26 µg/mL. The extracts inhibit porcine pancreatic lipase activity, demonstrating their potential as lipase inhibitors. Specifically, at a concentration of 1 mg/mL, the highest inhibition rate (77%) was observed for EDm. To confirm these results, the inhibitory effect of these extracts on enzymes was tested in vivo. The oral intake of aqueous extract markedly reduced starch- and sucrose-induced hyperglycemia in healthy rats. Administration of the ethanolic extract at a specific dose of 150 mg/kg significantly reduced postprandial glycemia compared with the control group. It is, therefore, undeniable that cannabis extracts represent a promising option as a potentially effective treatment for type 2 diabetes.

Vitamin C deficiency in critically ill COVID-19 patients admitted to intensive care unit.

To determine vitamin C plasma kinetics, through the measurement of vitamin C plasma concentrations, in critically ill Coronavirus infectious disease 2019 (COVID-19) patients, identifying eventually the onset of vitamin C deficiency. Prospective, observational, single-center study. Intensive Care Unit (ICU), Vall d'Hebron University Hospital, Barcelona. Study period from November 12th, 2020, to February 24th, 2021. Patients who had a severe hypoxemic acute respiratory failure due to COVID-19 were included. Plasma vitamin C concentrations were measured on days 1, 5, and 10 of ICU admission. There were no vitamin C enteral nor parenteral supplementation. The supportive treatment was performed following the standard of care or acute respiratory distress syndrome (ARDS) patients. Plasma vitamin C concentrations were analyzed using an ultra-performance liquid chromatography (UPLC) system with a photodiode array detector (wavelength set to 245 nm). We categorized plasmatic levels of vitamin C as follows: undetectable: < 1,5 mg/L, deficiency: <2 mg/L. Low plasma concentrations: 2-5 mg/L; (normal plasma concentration: > 5 mg/L). Forty-three patients were included (65% men; mean age 62 ± 10 years). The median Sequential Organ Failure Assessment (SOFA) score was 3 (1-4), and the Acute Physiology and Chronic Health disease Classification System (APACHE II) score was 13 (10-22). Five patients had shock. Bacterial coinfection was documented in 7 patients (16%). Initially all patients required high-flow oxygen therapy, and 23 (53%) further needed invasive mechanical ventilation during 21 (± 10) days. The worst PaO2/FIO2 registered was 93 (± 29). ICU and hospital survival were 77 and 74%, respectively. Low or undetectable levels remained constant throughout the study period in the vast majority of patients. This observational study showed vitamin C plasma levels were undetectable on ICU admission in 86% of patients with acute respiratory failure due to COVID-19 pneumonia requiring respiratory support. This finding remained consistent throughout the study period.

Development and validation of a UPLC-PDA method for quantifying ceftazidime in dried blood spots

Bacterial infection is a leading cause of neonatal death. Ceftazidime, commonly used for neonatal infections, is often used off-label. Blood sampling limits pharmacokinetic (PK) studies in neonatal patients. The dried blood spots (DBS) are a potential matrix for microsampling. Herein, we describe an ultra-performance liquid chromatography with a photodiode array (UPLC-PDA) to determine ceftazidime in DBS from neonatal patients in support of pharmacokinetic studies. The Capitainer® device-based DBS samples containing 10 µL blood were extracted in 70% methanol/water (v/v) with acetaminophen as the internal standard (IS). The extraction process was carried out at 20 °C using a block bath shaker at 1000 rpm for 30 min. The extracted ceftazidime was subsequently eluted through an Acquity UPLC HSS T3 column (2.1 × 50 mm, 1.8 µm). Elution was achieved using a water (containing 0.1% trifluoroacetic acid)/acetonitrile linear gradient at a flow rate of 0.5 mL/min, and the analytical time was 3.2 min. The PDA detection wavelength was set at 259 nm. The method underwent thorough validation following the recommendation of the European Bioanalysis Forum (EBF) and the bioanalytical guideline established by the European Medicines Agency (EMA). No interfering peaks were detected at the retention times of ceftazidime and IS. The ceftazidime exhibited a quantification range spanning from 0.5 to 200 µg/mL, and the assay demonstrated good accuracy (intra/inter-assay ranging from 90.1% to 104.8%) and precision (intra/inter-assay coefficient of variations ranging from 4.8% to 11.7%). The method's applicability was demonstrated by analyzing clinical DBS samples collected from neonatal patients.

Chimgin from Ferula haussknechtii as AChE inhibitor and confirmation of the absolute configuration

Alzheimer’s disease (AD) is the most common cause of dementia worldwide and is classified as a neurodegenerative disorder. From a drug design perspective, natural products (NPs) are more drug-like and are highly compatible with biological systems compared to most synthetic libraries. NPs provide a more efficient and cost-effective approach to new drug discovery. However, the complexity of NPs makes their identification a challenging task. Chimgin, a bicyclic monoterpene with three chiral centers, exhibits a wide range of biological activity. Despite this, the exact structure of chimgin has remained unclear until now. In this study, we quantified the amount of chimgin in Ferula haussknechtii using analytical Reversed-phase high-pressure liquid chromatography equipped with photodiode array detector (RP-HPLC-PDA). Furthermore, we determined the absolute configuration of chimgin through electronic circular dichroism (ECD) spectroscopy and time-dependent density functional theory (TDDFT) calculations. Finally, we evaluated its inhibitory effect on AChE through in vitro and in silico studies. The extraction process yielded an output of 2.82 ± 0.10% with an exact amount of 0.62 ± 0.04 mg of chimgin per 100 g of plant. Based on the results of ECD and TDDFT calculation, the absolute configuration of chimgin was determined to be 1S, 2S, 4S. Chimgin exhibited an inhibitory effect on AChE with an IC50 of 37.43 µM and its mechanism of action was found to be competitive. Highlights Chimgin was isolated from the roots of Ferula haussknechtii. The amount of chimgin in the plant was determined by RP-HPLC-PDA. Its absolute configuration of chimgin was determined using ECD. In vitro acetylcholinesterase activity of the chimgin was evaluated. The docking and molecular dynamic simulation of chimgin was done. Communicated by Ramaswamy H. Sarma

Simultaneous determination of enantiomeric residues of flutriafol, hexaconazole and diniconazole in fruits and vegetables on a bridged cyclodextrin-based column by HPLC

The new type of bis-triazolyl bridged cyclodextrin-based stationary phase (BCDP) was prepared through “Click reaction”. BCDP had high selectivity for triazoles and was used for the simultaneous fast separation and determination of enantiomeric residues (flutriafol, hexaconazole and diniconazole) in fruits and vegetables by high-performance liquid chromatography (HPLC). The QuEChERS method assisted by magnetic nanoparticles was used for sample pretreatment, and then a gradient elution was carried out by using MeOH-H2O as the mobile phase on BCDP to achieve rapid resolution of the triazole enantiomers within 25 min. After condition optimization, simultaneous baseline separations of the six enantiomers were achieved with resolutions of 1.54 (flutriafol), 2.27 (hexaconazole) and 1.97 (diniconazole). A new HPLC quantification method of the six enantiomeric residues in apples, tomatoes and cucumbers was established by an internal standard with a photo-diode array (PDA) detector at 210 nm. The results showed that the excellent linear relationships of all triazole enantiomers were observed in the concentration range of 0.5–50 mg L-1 (R2 = 0.9986–0.9999). The average recoveries of enantiomers in fruits and vegetables were from 91.95 % to 109.92 % with RSDs of 0.97 %–1.32 % for intraday and 1.30 %–3.03 % for interday. The limits of detection (LODs, S/N = 3) and limits of quantitation (LOQs, S/N = 10) of all enantiomers were less than 0.03 mg kg−1 and 0.10 mg kg−1, respectively. BCDP had high selectivity for triazole due to its synergistic inclusion with triazoles and advantage in fast and simultaneous separation of multiple triazole enantiomers, which could save analysis time and reduce solvent consumption. BCDP was a new separation material for the scientific evaluation of chiral pesticides in the food safety analysis.

Optical Phased Array-Based Laser Beam Array Subdivide Pixel Method for Improving Three-Dimensional Imaging Resolution

The small number of pixels in the current linear mode avalanche photodiode (LM-APD) array limits its three-dimensional (3D) imaging resolution. We use an optical phased array-based beam array subdivided pixel method to improve the 3D imaging resolution, using an optical phased array to generate a beam array with the same number of pixels as the LM-APD array and matching positions and controlling each sub-beam in the beam array to scan in the field of view of the corresponding pixel. The sub-beam divergence angle in the beam array is smaller than the instantaneous field of view angle of a single pixel in the LM-APD array. The sub-beam scanning in a single pixel’s field of view realizes the multiple acquisition of the target 3D information by the LM-APD array, thus improving the resolution of the LM-APD array. The distribution of the beam array in the far field is simulated, and the main performance parameters of 3D imaging are analyzed. Finally, a liquid crystal phase modulator is used as an optical phased array device to conduct experiments on a target 20 m away, and the results prove that our method can improve the resolution from 4 × 4 to 8 × 8, which can be improved at least four times.

A novel stability indicating mass compatible reversed‐phase high‐performance liquid chromatography for the determination of Diroximel fumarate and its related impurities

AbstractDiroximel fumarate (DRF) is a novel oral fumarate used in the treatment of multiple sclerosis. Comprehending DRF's stability behavior in different degradation conditions is crucial and has been studied under photolysis, oxidative, hydrolysis, and thermal conditions. Nucleosil C18 column (250 × 4.6 mm, 5 μm) was employed to achieve drug separation, with a mobile phase comprising of water and acetonitrile (65:35, v/v). The flow rate was 1 mL/min and detection was performed at 210 nm using a photodiode array detector. The fully validated reversed phase‐high‐performance liquid chromatography stability method as per the International Council for Harmonization Q2 R1 demonstrated excellent selectivity, accuracy, and precision with good sensitivity. During the analysis, two prominent degradant product peaks of DRF were identified across all stress conditions. The usage of liquid chromatography‐mass spectrometry compatible solvents in the mobile phase permits further characterization of DRF and its degradants peak. Significant levels of degradation were found in alkaline and acidic hydroxide, peroxide, photolytic, and thermal conditions with hydrolysis being postulated as a possible mechanism of degradation. The fully validated stability‐indicating analytical method can be used for routine quality control and stability testing of DRF, requiring storage in a protected primary container, as it is sensitive to light and moisture.

Valorization of black grape pomace by pressurized hot water extraction and hydrolysis: Real-time online and in-line monitoring

The primary aim of this study was to maximize the value of black grape pomace by harnessing innovative and environmentally friendly extraction and hydrolysis technology on the biorefinery concept. This automated system seamlessly integrates pressurized hot water extraction (PHWE) and sequential subcritical water hydrolysis (SubCWH), complemented by inline purification through solid phase extraction (SPE) and online analysis via high-performance liquid chromatography (HPLC) equipped with photodiode array (PDA) and refractive index (RI) detectors. The results of this investigation revealed the presence of twelve anthocyanins, each exceeding a concentration of 3 mgEC3G gDBGP-1. By summing the concentration of these individual anthocyanins, a total yield of 47.6 mgEC3G gDBGP-1 was achieved, attributed to the utilization of acidified water as the solvent and adherence to optimal process conditions. The newly developed system demonstrated its efficacy in both PHWE and SubCWH of black grape pomace, coupled with inline SPE purification and real-time HPLC analysis of various natural compounds. The real-time monitoring capability facilitated swift and efficient responses, reducing processing time, minimizing solvent consumption, decreasing labor requirements, conserving energy, and mitigating environmental impact.

Self-powered solar-blind detector array based on ε-Ga2O3 Schottky photodiodes for dual-mode binary UV communication

In this work, a solar-blind UV metal-semiconductor Schottky photodiode array is constructed by using metalorganic chemical vapor deposition grown ε-Ga2O3 thin film, possessing high-performance and self-powered characteristics, toward dual-mode (self-powered and biased modes) binary light communication. For the array unit, the responsivity, specific detectivity, and external quantum efficiency are 30.8 A/W/6.3 × 10−2 A/W, 1.51 × 104%/30.9%, 1.28 × 1014/5.4 × 1012 Jones for biased (−10 V)/self-powered operation. The rise and decay time are 0.19 and 7.96 ms at biased modes, respectively, suggesting an ability to trace fast light signal. As an array, the deviation of photocurrent is only 4.3%, highlighting the importance of accurate information communication. Through certain definition of “1/0” binary digital information, the “NY” and “IC” characters are communicated to illustrate the self-powered and biased modes by right of ASCII codes, based on the prepared ε-Ga2O3 solar-blind UV Schottky photodiode array. This work made dual-mode binary deep-UV light communication come true and may well guide the development of UV optoelectronics.

Simultaneous determination of capsanthin and capsorubin in foods by high-performance liquid chromatography using PDA detector

A high-performance liquid chromatography method with a photodiode array detector (HPLC-PDA) was developed for the simultaneous determination of Capsanthin and Capsorubin in food. These are the two main carotenoids responsible for the red color found in Capsicum annuum and lily (Lilium). Analytes were extracted by ultrasonic vibration method with solvent of acetonitrile (ACN): ethyl acetate containing 0.1% butyl hydroxytoluene (BHT) (1:1, v/v) at a temperature of 40oC for 20 minutes. The sample extract solution was determined by HPLC&amp;ndash;PDA with the following conditions: InterSustain C18 column (250 mm x 4.6 mm; 5 &amp;micro;m), mobile phase consisting of a 5 mM ammonium acetate solution, ACN, MeOH, and water following with gradient program, detection wavelength at 450 nm. The method has good specificity, the calibration curve of Capsanthin and Capsorubin has R2 &amp;gt; 0.9997 and the repeatability and recovery meet AOAC requirements. The limit of detection (LOD) and limit of quantification (LOQ) were 0.20 mg/kg and 0.67 mg/kg, respectively. The method was applied to simultaneously determine Capsanthin and Capsorubin in 35 different food products including chili powder, spices, soft drinks, canned products, confectionery, ice cream, and cheese. Capsanthin was detected with a content of 10.5-15.8 mg/kg in chili powder and 3.86-9.78 mg/kg in spices, capsorubin was detected with a content of 2.86-3.92 mg/kg in chili powder and 0.76 -1.64 mg/kg in spices.

Compact OWC Receiver: Micro-Lens and PD Array on Glass Interposer

In this paper, we propose a compact optical wireless receiver based on micro-lens and photodiode array flip-chipped on a glass interposer. With simulation models and experiments, we verify the performance of two optical wireless communication receivers assembled based on this structure with gigabit and high-speed photodiodes. First, co-integrated gigabit photodiodes and micro-lenses indicate that micro-lenses can deliver a 3.5 dB gain of light collection efficiency to the gigabit photodiode array while keeping the field of view larger than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 18 degrees. Besides, a 5.5 Gbps maximum throughput has been verified by this optical wireless communication receiver with discrete multitone modulation. Moreover, co-integrated high-speed photodiodes and micro-lenses prove that micro-lenses realize a 26.6 dB improvement in light collection efficiency, enabling a 10 Gbps error-free connection using as little as -0.5 dBm transmission power. Those results conclude that the co-integration of micro-lenses on the photodiode array can enhance the light collection efficiency of the photodiode array while keeping a larger field of view, providing a high-performance, low-cost solution for the receiver of optical wireless links.