Repeatability Relative Standard Deviation Research Articles

Establishment of chemical fingerprint and determination of main active ingredients in Centellae Herba by HPLC combined with multivariate chemometrics analysis

AbstractIn this paper, a simple and efficient high‐performance liquid chromatography method was established to analyze the chemical composition fingerprint of Centellae Herba (CHA) and determine five triterpenoid active components in CHA, namely, asiaticoside B (AB), madecassoside, asiaticoside, madecasic acid, and asiaticoic acid. The separation of the compounds was carried out on an XD‐C18 column (250 mm × 4.6 mm, 5 µm), the wavelength of the ultraviolet detector was set to 205 nm, and the mobile phase was composed of acetonitrile −0.05% phosphoric acid, 2 mmol/L β‐cyclodextrin aqueous solution, and gradient elution at the flow rate of 1.0 mL/min. A general chromatographic fingerprint consisting of 20 characteristic peaks of 18 batches of CHA samples was established, and the samples were classified and evaluated by similarity analysis, hierarchical cluster analysis, and principal component analysis combined with multivariate econometric analysis. In quantitative analysis, all calibration curves showed good linear regression in the test range (r > 0.999), the average recovery was 96.12%–104.63%, and the relative standard deviations of repeatability and stability were less than 2.00%. The results show that the method is accurate and effective and can be used for the comprehensive quality control of CHA.

Ultrasensitive Ochratoxin A Detection in Cereal Products Using a Fluorescent Aptasensor Based on RecJf Exonuclease-Assisted Target Recycling.

Ochratoxin A (OTA) is a mycotoxin widely found in foodstuffs such as cereal grains. It greatly threatens human health owing to its strong toxicity and high stability. Aptasensors have emerged as promising tools for the analysis of small molecule contaminants. Nucleic-acid-based signal amplification enables detectable signals to be obtained from aptasensors. However, this strategy often requires the use of complex primers or multiple enzymes, entailing problems such as complex system instability. Herein, we propose a fluorescent aptasensor for the ultrasensitive detection of OTA in cereal products, with signal amplification through RecJf exonuclease-assisted target recycling. The aptamer/fluorescein-labeled complementary DNA (cDNA-FAM) duplex was effectively used as the target-recognition unit as well as the potential substrate for RecJf exonuclease cleavage. When the target invaded the aptamer-cDNA-FAM duplex to release cDNA-FAM, RecJf exonuclease could cleave the aptamer bonded with the target and release the target. Thus, the target-triggered cleavage cycling would continuously generate cDNA-FAM as a signaling group, specifically amplifying the response signal. The proposed exonuclease-assisted fluorescent aptasensor exhibited a good linear relationship with OTA concentration in the range from 1 pg/mL to 10 ng/mL with an ultralow limit of detection (6.2 ng/kg of cereal). The analytical method showed that recoveries of the cereal samples ranged from 83.7 to 109.3% with a repeatability relative standard deviation below 8%. Importantly, the proposed strategy is expected to become a common detection model because it can be adapted for other targets by replacing the aptamer. Thus, this model can guide the development of facile approaches for point-of-care testing applications.

Preparation and characterization of vinyl silica‐supported surface molecularly imprinted polymers coupled with liquid chromatography‐mass spectrometry for extraction of prostaglandin analogs from cosmetic products

AbstractProstaglandin analogs (PGAs) are commonly used to treat ocular hypertension and glaucoma patients. Nowadays, the use of PGAs enhances eyelashes in cosmetics, particularly in the condition of hypotrichosis. A method was developed in which surface molecularly imprinted polymers were synthesized for selective extraction of PGAs (bimatoprost, latanoprost, and travoprost) by using bimatoprost as template molecules which were coupled with liquid chromatography‐mass spectrometry (LC‐MS) system. Scanning electron microscopy and Fourier‐transform infrared spectroscopy techniques were used to study the morphological and physical characterization. The adsorption selectivity studies showed the high selectivity of PGAs. The adsorption capacities of bimatoprost, latanoprost, and travoprost were 93.8, 92.3, and 91.5 μg/g, respectively. The recoveries and precision of samples at three concentration levels (10–30 ng/mL) of bimatoprost, latanoprost, and travoprost were tested (98.5%–102.5%, 1.2%–4.5%, n = 3). The % relative standard deviation for repeatability of the method for bimatoprost, latanoprost, and travoprost ranged from 1.8 to 5.6, 1.5 to 4.8, and 1.6 to 5.2, respectively. While the limit of detection for bimatoprost, latanoprost, and travoprost was 0.20, 0.25, and 0.45 ng/mL, respectively. The method of surface molecularly imprinted polymer coupled with LC‐MS was successfully applied to cosmetic products for selective extraction of PGAs.

Simultaneous determination of five carbapenems, highly polar antibiotics, in milk by LC-MS/MS

The simultaneous determination of five carbapenems (biapenem, doripenem, ertapenem, imipenem, and meropenem) in raw and pasteurised bovine milk samples using LC-MS/MS was achieved and validated. Chromatographic separation was conducted on an InertSustain® AQ-C18 column using 0.1% formic acid in water and acetonitrile as the mobile phase. Target compounds were extracted using acetonitrile/water (20:80, v/v). After the removal of lipids with acetonitrile-saturated hexane, the dissolved protein was denatured with acetic acid. A portion of the supernatant was passed through an Oasis® PRiME HLB cartridge to remove the matrix. This novel method was validated in accordance with the Japanese validation guidelines and exhibited good trueness, ranging from 86.3% to 96.2%, using matrix-matched calibration curves. The relative standard deviation of repeatability ranged from 1.0% to 6.3%, and that of within-laboratory reproducibility ranged from 1.6% to 7.1%. The limit of quantification was 1.0 µg kg−1 for all analytes. None of the 60 milk samples commercially available in Tokyo contained any analytes. This novel method exhibited high-quality performance and can easily be implemented for the routine monitoring of carbapenems, which are highly polar antibiotics in milk.

Development and validation of a method for the simultaneous quantitative analysis of the active forms of vitamins B1, B2, and B6 using 31P qNMR

With increasing demand for active vitamins in functional foods and supplements, accurate quantification is crucial to ensure that quality and safety standards are met. This study presents the development of a phosphorous-31 quantitative nuclear magnetic resonance (31P qNMR) spectroscopy method for the simultaneous analysis of the active forms of vitamins B1, B2, and B6 in multivitamin supplements. The 31P NMR signals of the analytes and internal standard were effectively resolved and easily distinguishable. The method was validated in terms of specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, and stability. The curves for all three vitamins exhibited a high degree of linearity, with correlation coefficients (R2) exceeding 0.999. The LOD (0.04–0.07 mg mL−1) and the LOQ (0.14–0.24 mg mL−1) were adequate for analysis of multivitamin supplements, and the accuracy (99.2–102.0%) was excellent. The relative standard deviations for repeatability (1.06–1.89%) and intermediate precision (2.51–3.25%) were considered acceptable. The developed 31P qNMR method was successfully applied to commercial multivitamin supplements, demonstrating its practicality. Therefore, the 31P qNMR method is expected to be suitable for the simultaneous quantification of active vitamins B1, B2, and B6 and an effective analysis method for multivitamin preparations.

All-solid-state chip utilizing molecular imprinted polymer for erythromycin detection in milk samples: Printed circuit board-based potentiometric system

Detection of erythromycin (ERY) residues in commercial milk samples is crucial for the safety assessment. Herein, a printed circuit board was patterned as a feasible miniaturized potentiometric sensor for ERY determination in dairy samples. The proposed chip design fits to a 3.5-mm female audio plug to facilitate the potential measurements of working electrode versus reference one in this all-solid-state system. The sensor utilizes molecular imprinted polymer (MIP) for the selective recognition of the studied drug in such challenging matrix. The electrode stability is achieved through the addition of poly (3,4-ethylenedioxythiophene) nano-dispersion on its surface. The proposed device detects down to 6.6 × 10−8 M ERY with a slope of 51 mV/decade in the 1 × 10−7–1 × 10−3 M range. The results display high accuracy (99.9% ± 2.6) with satisfactory relative standard deviation for repeatability (1.6%) and reproducibility (5.0%). The effect of common antibiotic classes, namely, amphenicols, beta-lactams, fluoroquinolones, sulfonamides, and tetracyclines, can be neglected as evidenced by their calculated binding capacities towards the proposed MIP. The calculated selectivity coefficients also show a good electrode performance in the presence of naturally present inorganic ions allowing its application to different milk samples.Graphical abstract

Trace arsenic quantification by hydride generation-flame atomic absorption spectrometry using durian husk-derived nanocellulose as a solid-phase extraction biosorbent

<p>In the present study, nanocellulose was successfully extracted from durian husk via chemical treatment and then characterized by several analytical techniques, involving X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). Nanocellulose was obtained with a crystallinity index of 77% and in the form of cellulose nanofibrils (30 nm in width and micrometers in length). Using nanocellulose as a biosorbent in solid-phase extraction technique, the inorganic arsenic ions were eluted using 0.1 M HNO3 and its content in the eluate solution was quantified by hydride generation-flame atomic absorption spectrometry (HG-FAAS), in which the recovery of arsenic ions using nanocellulose were assessed via contact time, pH and dosage of sorbent, reaching the equilibrium after 30 minutes. With the limit of detection (LOD) of 0.41 ng mL-1, the limit of quantification (LOQ) of 1.38 ng mL-1 and the relative standard deviation of repeatability (%RSD) of 3.44% (with ten replicates) for arsenic determination, the present method was practiced with the trace inorganic arsenic quantification in real samples (fish sauce with various protein levels) with reliable spike recoveries.</p>

Deep Eutectic Solvent-based green extraction and gas chromatography determination of phthalates released from food contact materials

A sensitive and efficient green emulsification liquid-liquid microextraction (ELLME) method using deep eutectic solvents (DES) for extraction of phthalates released from food contact materials (FCMs) was optimized for GC-MS determination of Butyl Benzyl Phthalate (BBP) and Di-2-Ethylhexyl Phthalate (DEHP). The optimal DES system for phthalate extraction was determined to be Choline Chloride:Phenol (1:2 molar ratio). Tetrahydrofuran (THF) was utilized as the emulsifier solvent. The effects of vortex agitation times and centrifugation times on extraction efficiency were investigated. The method yielded quantification limits (LOQ) of 0.036 and 0.005 mgL-1 for BBP and DEHP, respectively. Repeatability relative standard deviations (RSDr) of 2.9% and 2.2% were obtained for BBP and DEHP, respectively, while corresponding medium precision relative standard deviations (RSDR) were 2.8% and 3.2%. Recovery rates from spiked samples were 94.8% for BBP and 95.1% for DEHP. Finally, determination of BBP and DEHP released from contact materials into water and beverage samples at various temperatures confirmed the applicability of the method for assessment of phthalates and their migration from FCMs.

Validation of the CompactDry "Nissui" BC for Enumeration of Bacillus cereus in a Variety of Foods: AOAC Performance Tested MethodSM 092201.

The CompactDry "Nissui" BC is a ready-to-use dry media sheet using a chromogenic medium with selective agents for the detection and enumeration of Bacillus cereus in products after incubation at 30 ± 1°C for 24 ± 2 h. The CompactDry "Nissui" BC method was validated to achieve AOAC Performance Tested MethodsSM certification. The performance of the CompactDry "Nissui" BC was compared to that of ISO 7932:2004 for 10 matrixes, including panna cotta, double cream, dried baby food, dried vegetable soup mix, seafood sticks, salmon pâté, sliced ham, pork liver pâté, ham and cheese sandwich, and Caesar pasta salad with chicken and bacon. Performance indicators included repeatability, difference of means (DOM), and inclusivity/exclusivity. After log10 transformation of the data, the relative standard deviation of repeatability (RSDr) was ≤9.2% for 28 of the 30 materials (10 matrixes each at three contamination levels) analyzed by the CompactDry "Nissui" BC method and ≤13% for 27 of the 30 matrix/level combinations analyzed by the reference method. Method equivalence was demonstrated in 28 of the 30 matrix/level combinations based on the 90% confidence interval of the DOM being within (-0.5, 0.5). For inclusivity, 47 of 50 strains tested showed typical colonies and confirmed positive. For exclusivity, 28 of 33 strains tested resulted in no growth or were negative, and five were positive. Inclusivity and exclusivity results were similar on the reference method agar. The method was shown to be robust to changes in sample volume, incubation temperature, and incubation time, and data are presented supporting product consistency and 18-month shelf life. The CompactDry "Nissui" BC method is validated for the determination of Bacillus cereus in a variety of matrixes. The CompactDry "Nissui" BC method is equivalent to the ISO 7932:2004 reference method and is suitable for Performance Tested MethodsSM certification for the matrixes tested.

Quantification of Lactose in Lactose-Free and Low-Lactose Milk and Milk Products by BIOMILK 300/3000 Lac, Collaborative Study: Final Action 2020.09.

In April 2020, the BIOMILK 300 LAC method for the quantification of lactose in lactose-free and low-lactose dairy products was adopted as First Action Official Method of AnalysisSM2020.09 by AOAC INTERNATIONAL. To test the reproducibility of the method, as the last step toward the Final Action status, a collaborative study was organized by BIOLAN Microbiosensores. Fifteen collaborators within the European Union took part in this study, where nine different samples were sent as duplicate blind test portions for lactose determination. The data obtained were used to determine method repeatability and reproducibility and also to validate the new version of the biosensor. The test method is based on the direct enzymatic recognition-electrochemical detection of trace levels of lactose over a wide range of dairy samples by means of the BIOMILK 300 biosensor, in less than 5 min, and without intricate sample pretreatments. All samples resulted in a repeatability relative standard deviation (RSDr) of <8.1% and a reproducibility relative standard deviation (RSDR) of 14% maximum, meeting requirements from Standard Method Performance Requirement (SMPR®) 2018.09. The method has proved to give reproducible results for the quantification of lactose in lactose-free and low-lactose dairy products. On the basis of these results, the enzymatic amperometric biosensor method developed by BIOLAN Microbiosensores was adopted as a Final Action Official Method in July 2022.

Proteomic identification and quantification of Clostridium perfringens enterotoxin using a stable isotope-labelled peptide via liquid chromatography-tandem mass spectrometry.

Detection of Clostridium perfringens enterotoxin (CPE) in human stool is critical evidence of food poisoning. However, processing patient-derived samples is difficult and very few methods exist to confirm the presence of CPE. In this study, a technique was developed using proteomic analysis to identify and quantify CPE in artificial gut fluid as an alternative. The standard CPE was spiked into artificial gut fluids, and effective methods were developed by employing both a stable isotope-labelled internal standard peptide and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Proteotypic peptide EILDLAAATER formed by tryptic digestion was selected for quantitation of CPE. The peptide was identified using product ion spectra. Although the nontoxic peptides originating from CPE showed very low detectability in extraction and tryptic digestion, they could be detected with sufficient sensitivity using the method we developed. Based on a spiked recovery test at two concentrations (50 and 200µg/kg), the recovery values were 85 and 78%, respectively. The relative standard deviations of repeatability and within-laboratory reproducibility were less than 8 and 11%, respectively. These standard deviations satisfied the criteria of the Japanese validation guidelines for residues (MHLW 2010, Director Notice, Syoku-An No. 1224-1). The limit of quantification (LOQ) was estimated to be 50µg/kg. The combination of the product ion spectra and relative ion ratio supported CPE identification at the LOQ level. To the best of our knowledge, this is the first report of proteomic analysis of CPE using LC-MS/MS. The method would greatly help in assessing CPE reliably.

Multi-Techniques for Iodine Determination and Dose Uniformity Assays in Iodized Mineral Dietary Supplements

The determination of iodine in iodized mineral dietary supplements is considered a challenge, especially in view of the variety in the sample composition and the analyte concentration. Thus, in this work, microwave-induced combustion (MIC) was combined with ion chromatography (IC) and ion-selective electrode potentiometry (ISE) for iodine determination and dose uniformity assays in mineral dietary supplements. Sample masses up to 800 mg were efficiently digested and only a diluted alkaline solution (200 mmol L-1 NH4OH) was necessary to absorb the analyte for further determination step. The final digest was fully compatible with multi-technique detection usually available in routine analysis laboratories. Recoveries ranging from 94% to 106% was achieved and relative standard deviations for repeatability and intermediate precision were always lower than 8%. Limits of quantification were 4 µg g-1 and 10 µg g-1, respectively, by using IC and ISE. The analytical method was applied for iodine determination in mineral dietary supplements from four brands with different iodine dosages (from 100 to 1250 μg g-1, according to the manufacturers) and for uniformity assay evaluation using individual tablets/capsules of mineral dietary supplements. Non-compliance regarding label information for some samples was reported, drawing the attention of supervisory institutions. The analytical strategies presented in the present study can be successfully used in routine analysis of the quality control of mineral dietary supplements.

Synthesis and Application of Domestic Glassy Carbon TiO2 Nanocomposite for Electrocatalytic Triclosan Detection

Nanoparticles of TiO2 are suitable for many catalytic and photocatalytic applications due to their extraordinary properties such as superhydrophobicity, semiconductivity, electron-rich, and environmental compatibility. The main crystalline phases of TiO2, anatase, and rutile possess different crystal structures, crystallinity, crystalline sizes, and specific surface areas, and these characteristics directly affect the catalytic performance of TiO2. In the present study, domestic carbon material enhanced with TiO2 nanoparticles was synthesized and used for the construction of a modified carbon paste electrode. The electrocatalytic activity of the modified electrodes was investigated depending on the TiO2 crystalline phases in the electrode material. Furthermore, the obtained working electrode was utilized for triclosan detection. Under optimized experimental conditions, the developed electrode showed a submicromolar triclosan detection limit of 0.07 µM and a wide linear range of 0.1 to 15 µM. The relative standard deviations for repeatability and reproducibility were lower than 4.1%, and with satisfactory selectivity, the proposed system was successfully applied to triclosan monitoring in groundwater. All these results confirm that the sustainable production of new and domestically prepared materials is of great benefit in the field of electrocatalysis and that the morphology of such produced materials is strongly related to their catalytic properties.

Profiling Selected Volatiles in Whiskey by Fizzy Extraction Time-of-Flight Mass Spectrometry: Correlation with Perceived Quality and Age

Fizzy extraction (FE) is an extraction technique that extracts volatile organic compounds (VOCs) from liquid matrices using pressure-induced effervescence. The sudden decompression of a gas-saturated sample solution generates numerous microbubbles, which trap and transfer VOCs with different volatilities from the liquid phase into the headspace of the sample solution. Here, we coupled FE with an atmospheric pressure chemical ionization interface of a quadrupole time-of-flight mass spectrometry system to perform analysis of VOCs present in whiskeys. The hyphenated system has been optimized by using chemical standards. The optimized conditions are the following: saturation time, 40 s; equilibration time, 0 s; extraction time, 20 s; extract transfer tubing I.D., 1.0 mm; extract transfer tubing length, 80 cm. The limits of detection for ethyl acetate, ethyl propionate, ethyl butanoate, ethyl hexanoate, and ethyl octanoate are 7.48 × 10–8, 2.41 × 10–8, 1.63 × 10–9, 9.31 × 10–9, and 5.24 × 10–9 M, respectively. The repeatability relative standard deviations (RSDs) ranged from 6.00 to 12.17% (10 replicates on one day) while the reproducibility RSDs ranged from 4.01 to 11.47% (3 replicates on each of 6 different days). The resulting method was applied in analysis of 40 whiskeys originating from different countries or distilleries. The VOC profiles were used to characterize the whiskeys’ quality and age. Ethyl propionate and ethyl butanoate were found to be potential markers of whiskeys’ quality (using price per mL as the proxy of quality). In some cases, the concentrations of selected volatiles were found to increase when the age of whiskey increased. Additionally, we also determined the losses of selected volatiles in whiskey by analyzing the whiskey recurrently after opening the bottle. Overall, the developed method provides a fast (∼3 min), reliable, and green way to analyze VOCs in whiskey samples.

Validation of the Test Method-Determination of Available Carbohydrates in Cereal and Cereal Products, Dairy Products, Vegetables, Fruit, and Related Food Products and Animal Feeds: Collaborative Study, Final Action 2020.07.

A simple, accurate, and reliable method to measure available carbohydrate components of food products, including cereal and dairy products, fruits, vegetables, processed food, food ingredients, and animal foods, was developed by Megazyme (product K-AVCHO, Bray, Ireland). A single-laboratory validation of the enzymatic method resulted in First Action status as Official Method of AnalysisSM2020.07. A collaborative study was conducted to evaluate the repeatability and reproducibility of Official Method 2020.07 for the measurement of available carbohydrates, including digestible starch, lactose, sucrose, isomaltose, maltose, glucose, fructose, and galactose in a broad range of food and feed products. Samples are defatted if containing >10% fat content, and incubated with pancreatic α-amylase and amyloglucosidase under conditions that simulate those in the small intestine (pH 6, 37°C, 4 h). The reaction solution is clarified and diluted, and an aliquot is incubated with sucrase, maltase, oligo-1,6-α-glucosidase, and β-galactosidase to hydrolyze sucrose, maltose, isomaltose, and lactose to glucose, fructose, and galactose, which are then measured enzymatically. The multi-laboratory validation (MLV) matrixes included cereal, animal feeds, fruit, vegetables, infant formula, powdered milk drink, a dessert product, and mushrooms. Additional materials were analyzed by collaborators as "practice samples." All MLV matrixes resulted in repeatability relative standard deviations (RSDr) <3.91% and reproducibility relative standard deviations (RSDR) ranging from 3.51 to 11.58% with 9 of the 10 matrixes having RSDR of <6.19%. For the practice samples, the RSDR ranged from 2.7 to 11.4% with 7 of the 8 samples having RSDR of <4.4%. Official Method 2020.07 meets the AOAC requirements for repeatability and reproducibility, and the data support Final Action status. Official Method 2020.07 is a robust, simple to use, and reproducible method for the analysis of available carbohydrates in a wide range of matrixes.

Research and application of direct mercury analyzer (DMA-80) quickly determination of total mercury contents in dietary supplements

The Direct Mercury Analyzer (DMA-80) was studied and investigated to quickly and&amp;nbsp;accurately determine the total mercury content in health supplements. The method shows&amp;nbsp;high specificity, and the calibration curve has a good correlation coefficient with R2 greater&amp;nbsp;than 0.995; the limit of detection (LOD) and limit of quantification (LOQ) were 1.88 &amp;micro;g/kg&amp;nbsp;and 6.26 &amp;micro;g/kg, respectively; The relative repeatability standard deviation (RSRr) was in the&amp;nbsp;range of 2.46 - 7.34% and the recovery (R) was in the range of 85.7 - 100%. The method&amp;nbsp;was applied to evaluate the mercury content in 39 health supplement samples taken in Hanoi&amp;nbsp;city. The initial research results indicated preliminary&amp;nbsp;mercury&amp;nbsp;contamination in 13 health&amp;nbsp;supplement products on the market in the range of 5.41 - 450 &amp;micro;g/kg. &amp;nbsp;

Development and validation of a multi-residue method for determination of antimicrobial sulfonamides, macrolides and quinolones in Iranian feta cheese by SPE clean-up and LC-MS/MS

A selective and sensitive multi-residue/multi-class ultra-performance liquid chromatography–tandem mass spectrometry method has been validated for simultaneous analysis of 25 antibiotic residues belong to sulfonamides, macrolides, and quinolones groups, as well as griseofulvin and trimethoprim, in Iranian feta cheese samples. Two specific precursor – product ion transitions were acquired per target compound by a positive electrospray ionisation in multiple reaction monitoring mode. Results were obtained as follows: limit of detection (LOD) and limit of quantification (LOQ) were respectively 3.3 ng g−1 and 10 ng g−1 (except for josamycin, LOD: 8.33 and LOQ: 25 ng g−1). Average recovery ranged between 70% and 120% and relative standard deviation of repeatability was lower than 20%. Finally, the method was applied to determination of target analytes in feta cheese samples obtained from the local hypermarkets and traditional dairy product markets in Tehran, Iran.

A Portable Optical Fiber Tip Facet LSPR Aptasensor for Detection of Fumonisin B1

Fumonisin B1 (FB1) is a mycotoxin that mainly contaminates food crops. To avoid the harmful effect of FB1 on the human body, it is necessary to establish a convenient, sensitive, and accurate FB1 detection method. In this study, an optical fiber tip facet biosensor based on the localized surface plasmon resonance (LSPR) that adapts to a general detection platform was developed. An optical fiber end face was assembled with –NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , Au nanoparticles (AuNPs), and aptamer, and the fabricating parameters were optimized. The results showed that the optical fiber LSPR biosensor had a good linear relationship ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}^{\text {2}}$ </tex-math></inline-formula> = 0.9817) between the logarithmic FB1 concentration and the LSPR peak shifts within the linear range of concentrations of 0.8–200.0 ng/mL and a low limit of detection (LOD) of 0.17 ng/mL, as well as selectivity, recovery rates (96.08%–112.23%), and repeatability relative standard deviation (RSD) of 3.37%. It was validated by corn. Therefore, it was feasible that a tip facet optical fiber LSPR biosensor could be used to detect FB1, with advantages of convenience, renewability, and low cost. It is easy to popularize and apply.

Preformulation and UV-Spectrophotometric Analytical Method Validation Studies for Assessment of Canagliflozin

&gt;The objectives of the present investigation were the physicochemical examination of canagliflozin to authenticate the drug’s characteristics and validation of straightforward and rapid ultraviolet-spectroscopy technique for evaluation of canagliflozin in phosphate buffer, pH 6.8. X-ray diffraction study revealed numerous peaks i.e. 11.41, 16.35, 16.5, 16.65, 18.53, 18.58, 19.55, 20.11, 20.46, 20.71, 21.62, 23.96, 24.17, 24.77, 26.5, 27.08, 27.68, 28.22, 28.73 and 32.6 at °2θ which demonstrated extremely crystalline character of drug. The regression equation for the standard plot was Y = 0.01957X + 0.036, and correlation coefficient was 0.9936. The method was found linear as indicated by correlation coefficient values of 0.9933, 0.9938, and 0.9943 for three consecutive standard plots. The average recovery of Canagliflozin was found to be 100.033% which was inside the prerequisite specification of the range 98 to 102%. The percentage relative standard deviation for repeatability, inter-day precision, intermediate precision, and robustness was less than 2%. The limit of detection (LoD) for Canagliflozin was 2.38 μg/mL, and the limit of quantitation was 7.24 μg/mL, which established the sensitivity of the UV-spectroscopy analytical method. In conclusion, the validation parameters like linearity, accuracy, repeatability, inter-day precision, intermediate precision, robustness, and sensitivity were found acceptable for the UV-spectroscopy analytical technique for analysis of Canagliflozin.

Quality by design assisted high‐performance liquid chromatography parameters for simultaneous estimation of simvastatin and fenofibrate

AbstractIn a present study quality by design was used to develop a reliable high‐performance liquid chromatography method for simultaneous estimation of simvastatin and fenofibrate. A robust chromatographic setting for quality peaks and appropriate component separation within a reasonable run duration was generated. Furthermore, to determine critical quality attributes (CQA), a quantitative relationship between critical material attributes and CQA was established using Box‐Behnken design to produce analytical design space and develop a control approach. The mathematical models used three independent characteristics, acetonitrile volume, buffer molarity, and flow rate. The optimum and expected conditions were acetonitrile and potassium dihydrogen orthophosphate buffer (pH 2.9 adjusted, with orthophosphoric acid) (80.65:19.35 v/v) as an optimized mobile phase at a flow rate of 0.99 ml/min. We achieved adequate baseline separation of both drugs in just 10 min with these optimum parameters. The amount of acetonitrile was revealed to be the most important factor determining the perturbation plot responses. The %recoveries for both medicines were 99.15%–101.86% at all three levels. Both drugs showed relative standard deviations for repeatability, and intermediate precision were less than 2%. As a result, a simple, accurate, and repeatable high‐performance liquid chromatography approach for routine quality control testing was developed.