Relative Standard Deviation Research Articles

Determination of some indicator polychlorinated biphenyls (I-PCBs) in foods by gas chromatography tandem mass spectrometry (GC-MS/MS)

Polychlorinated biphenyls (PCBs) are toxic chemicals that persist in the environment and can accumulate in the food chain. The study was conducted with the aim of developing a method to determine the content of 6 I-PCBs compounds by gas chromatography-mass spectrometry (GC-MS/MS) combined with Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) technique for sample treatment. The sample was extracted with acetonitrile (ACN) solvent and cleaned with PSA adsorbent. The cleaned extract was analyzed on a GCMS/MS system with a DB-5MS column (30 m × 0.25 mm × 0.25 µm). The method had good specificity, the linear range was established in the range of 1.5-40 ng/g, the correlation coefficient R2 > 0.999. The method recovery was 74.5-102.7% and the relative standard deviation (RSD%) ranged from 0.9-6.20% for milk and meat samples. The method's limit of detection (LOD) and limit of quantification (LOQ) for 6 I-PCBs were 0.5 ng/g and 1.5 ng/g, respectively. The method was applied to analyze the content of 6 I-PCBs in 40 food samples (meat and meat products, milk and dairy products) randomly purchased in Hanoi. The results showed that in all 40 analyzed samples, 1 powdered milk sample detected PCB-28 and PCB- 101, the total content of I-PCBs was 13.0 ng/g fat lower than the European regulations.

Facile nanofabrication and simultaneous color-and-Raman hybrid mechanism of economic SERS substrate with tunable structure color for high enhancement factor

The conventional SERS technique utilizing metal nanoparticles (MNPs) is a powerful optical sensing method, relying on the inelastic collision between incident light and the analyte. However, the development of traditional color-tunable MNP-SERS substrates remains limited to two separate components of the color supporter for generating structure color and followed by the MNPs coating to generate the localized surface plasmonic resonance for SERS sensing. Here, a novel color-tunable SERS substrate without MNPs based on the economic one-step anodic aluminum oxide (AAO) coated with nanoporous Pt films was proposed to generate the color-and-Raman hybrid effect for high enhancement factor. This novel SERS substrate employs an economic method, that is a facile and low-cost one-step anodization process to fabricate the AAO with tunable structure color, enabling adaptation to excitation of laser sources. The substrate with the lowest reflectance to laser light exhibits the highest enhancement factor due to the coupling between the laser and the substrate. The resultant SERS substrate demonstrates a high enhancement factor (EF) of 5.27x105 to methylene blue with a good uniformity of the relative standard deviation (RSD) of 6.35 %. In a practical application, one of preservative, benzoic acid, was detected with a low concentration of 1 ppm in the extraction solution of tapioca balls. This innovative approach promotes limitations associated with traditional color-tunable SERS substrates and offers a promising path for sensitive and versatile trace substance detection.

Sensitive detection of Vibrio parahaemolyticus via a dual-recognition colorimetric biosensor comprising Cefe-PEG-MNPs and apt-Fe@PDA

Highly accurate and sensitive detection of Vibrio parahaemolyticus is crucial for ensuring seafood safety and preventing the transmission of foodborne diseases. Herein, a dual-recognition strategy-driven colorimetric biosensor for the detection of V. parahaemolyticus was developed. This biosensor was based on the use of PEG-mediated cefepime-functionalized magnetic nanoparticles (Cefe-PEG-MNPs) and aptamer-modified Fe-doped polydopamine (Fe@PDA) nanozymes. The magnetic platform Cefe-PEG-MNPs was introduced to enhance the enrichment efficiency of V. parahaemolyticus, achieving a capture efficiency exceeding 90%. The Fe@PDA nanozyme exhibited notable peroxidase mimetic enzyme activity. The colorimetric biosensor developed for V. parahaemolyticus detection demonstrated good sensitivity, with a detection range spanning from 2.1 × 101 to 2.1 × 106 CFU/mL, and a limit of detection of 21 CFU/mL. Moreover, the biosensor demonstrated remarkable specificity, achieving good recovery rates from 95.80% to 103.80% in Penaeus vannamei with a relative standard deviation of less than 1.38%. The newly developed colorimetric biosensor offers a remarkable opportunity for the accurate and sensitive detection of V. parahaemolyticus in seafood.

A bioinspired porous and electroactive reduced graphene oxide hydrogel based biosensing platform for efficient detection of tumor necrosis factor-α.

Oral cancer is one of the leading cancer types, which is frequently diagnosed at an advanced stage, giving patients a poor prognosis and fewer therapeutic choices. To address this gap, exploiting biosensors utilizing anti-biofouling hydrogels for early-stage oral cancer detection in non-invasive body fluids is gaining utter importance. Herein, we have demonstrated the fabrication of an innovative electrochemical immunosensor for the rapid, label-free, non-invasive, and affordable detection of tumor necrosis factor-α (TNF-α), a biomarker associated with oral cancer progression in artificial saliva samples. The gold screen-printed electrodes (gSPEs) are modified with a green synthesized porous and electroactive reduced graphene oxide (rGO) hydrogel utilizing L-cystine (L-cys) as both in situ reducing and surface functionalization agent, followed by covalent immobilization of anti-TNF-α and blocking of residual sites with bovine serum albumin (BSA) to fabricate the BSA/anti-TNF-α/L-cys_rGO hydrogel/gSPE immunosensing platform. The fabricated platform demonstrates excellent performance, with a low limit of detection of 1.20 pg mL-1, a broad linear range from 1 to 200 pg mL-1, and a high sensitivity of 2.10 μA pg-1 mL cm-2 carried out with differential pulse voltammetry (DPV) technique. Moreover, it exhibits specificity towards TNF-α, even in the presence of potential interferents and other cancer biomarkers. Besides, the biosensor showed good reproducibility and repeatability with a relative standard deviation (%RSD) of 5.11% and 1.85%, respectively. Thus, integrating the L-cys_rGO hydrogel in the immunosensor design offers enhanced performance, paving the way for its application in early-stage oral cancer diagnosis.

Head Space GC-MS/MS Method for Quantification of Five Nitrosoamine-Genotoxic Impurities in Metformin HCl

Background: N-nitrosamines have recently been discovered in metformin hydrochloride and other generic drugs. To quantify the five N-nitrosamines in metformin hydrochloride, we devised sensitive and reliable multiple reactions monitoring mode-based GCMS/ MS technique, particularly, N-nitrosodiethy amine (NDEA), N-nitroso ethyl isopropylamine (NEIPA), N-nitrosodiisopropylamine (NDIPA), N-nitrosodipropylamine (NDPA), as well as N-nitrosodibutylamine (NDBA). Objective: To develop a sensitive, precise, and accurate MRM mode based GC-MS/MS method for the quantification of five N-nitrosamines in metformin hydrochloride and valídate as per ICH guidelines. Methods: The settings for mass spectrometry and gas chromatography were optimized. With the linearity, sensitivity, specificity, accuracy, and precision of the parameter, the procedure was as per the recommendation of ICH: International Council for Harmonization guidelines. Results: N-nitrosamines in metformin hydrochloride had detection and quantification limits of 0.001 ppm and 0.004 ppm, correspondingly. The obtained results were within the sensitivity limitations issued by the US Food and Drug Administration. The calibration curve's regression coefficients for five N-nitrosamines were over 0.99, demonstrating the process's good linearity. The retrievals of N-nitrosamines in metformin hydrochloride between 97.1 – 127.4 %. The RSD (Relative Standard Deviation) was lower than 10 % for both inter-day and intra-day precision studies. Conclusion: The proposed method exhibited a rapid analysis capability, high accuracy, sensitivity, and precision, making it a trustworthy method for monitoring N-nitrosamines in metformin hydrochloride.

A Virtual Reality Tool for Accuracy Assessment of 3D Models in an Immersive Virtual Environment

Abstract. Accurate validation and assessment techniques are essential for ensuring the reliability of spatial reconstructions derived from photogrammetry, enabling well-informed decision-making across diverse domains. This study presents a Virtual Reality (VR) based accuracy assessment tool tailored for evaluating the accuracy and quality of 3D models generated by Unmanned Aerial Vehicles (UAVs). Leveraging the Unity game engine platform, our workflow entails three key steps: aligning real-world coordinates with an arbitrary Unity coordinate system, transforming the positions of Ground Control Points (GCPs) from field survey to the arbitrary system using a reference GCP, and marking observed points on the 3D models. Absolute and Relative Root Mean Square Errors (RMSE), Mean Errors (ME), and Standard Deviation of errors (SD) are computed within the virtual environment via the game object transform properties. The error distributions around each GCP are visually depicted using Unity game engine components for enhanced interaction and comprehension. The efficacy of the tool is validated through experimentation on four 3D models generated from varying camera angles during UAV data capture. The tool provides the opportunity to directly interact with the 3D models and visualize the errors, which is quite distinct from traditional methods. Using the developed tool, results were obtained to indicate that configurations employing camera angles of 60° + 75º exhibit notable performance in terms of relative and absolute accuracy.

Aptamer-Conjugated Covalent-Organic Framework Nanochannels for Selective and Sensitive Detection of Aflatoxin B1.

Sensitive and selective detection of trace aflatoxin B1 (AFB1) in foods is of great importance to guarantee food safety and quality but still challenging because of its trace amount and the interference from the complex food matrix. Here, we report the integration of aptamer (Apt) and an ordered 2D covalent organic framework (COF) to solid-state anodic aluminum oxide (AAO) nanochannels (Apt/COF/AAO) for selective and sensitive detection of trace AFB1. The high specificity of Apt for AFB1 led to a selective change in the surface charge of Apt/COF/AAO and in turn the current change of the nanochannel, permitting the selective and sensitive determination of trace AFB1 in complex food samples. The developed nanofluidic sensor gave a wide linear range (1-500 pg mL-1), low detection limit (0.11 pg mL-1), and good precision (relative standard deviation of 1.5% for 11 replicate determinations of 100 pg mL-1). In addition, the developed sensor was successfully used for the detection of AFB1 in food samples with the recovery of 86.9%-102.5%. The coupling of Apt-conjugated 2D COF with an AAO nanochannel provides a promising way for sensitive and selective determination of food contaminants in complex samples.

Distance-based analytical device integrated with carbon nanomaterials for sarcosine quantification in human samples.

Astraightforward distance-based paper analytical device (dPAD) was developedfor monitoring sarcosine levels in human samples for the rapid diagnosis and prognosis of prostate cancer and related symptoms. This assay eliminates the need for the expensive horseradish peroxidase (HRP) enzyme by utilizing carbon nanodots (CDs) as a peroxidase-like nanozyme. The proposed dPAD sensor consists of a sample zone pre-deposited with sarcosine oxidase (SOx) and CDs, and a detection zone containing 3,3',5,5'-tetramethylbenzidine (TMB). When a solution containing sarcosine is added to the sample zone, hydroxyl radicals (•OH) are produced through SOx oxidation and subsequent peroxidase catalysis by the CDs. The formed •OH radicals immediately flow to the detection zone via capillary force, where they oxidize TMB, resulting in a visible colour change from colourless to blue. Sarcosine quantification is effortlessly accomplished by measuring the distance of the blue colour in the detection zone. The developed dPAD offers a linear working range between 12.5 and 35.0nmol L-1 (R2 = 0.9959) and a detection limit (LOD) of 10.0nmol L-1. This covers the clinical range for urinary sarcosine determination, thereby suggesting no additional sample preparation or dilution is needed. The sensor shows high precision with the highest relative standard deviation (RSD) of 4.58% and demonstrates excellent selectivity with no observed interferences. Furthermore, recovery studies in human control urine samples ranged from 98.67 to 101.50%, with the highest RSD of 2.03%. Correspondingly, our dPAD method showed a great match with the performance of a commercial ELISA method for detecting sarcosine in human control serum. The sensor is more cost-effective, user-friendly, and accessible than previous methods. Overall, the proposed method represents a promising analytical tool for sarcosine quantification. The concept is also applicable for broader analytical applications in detecting other biomolecules.

Portable Miniature Mass Spectrometry for Enhanced On-Site Detection of Analytes in Complex Samples by Integrating Solid-Phase Microextraction and Nano-Electrospray Ionization.

On-site mass spectrometry (MS) analysis plays a crucial role in timely understanding chemical compositions of field samples but presents a challenge to miniaturization, portability, and sensitivity. In this work, a portable MS approach was developed by integrating biocompatible solid-phase microextraction (SPME) and a nano-electrospray ionization (nESI) emitter into a kit to couple miniature MS (mMS). The SPME fiber was used for on-site extractive sampling of analytes from complex liquid samples and living organisms and was then inserted into an nESI emitter for on-site MS analysis via the facile kit. The limit of detection was found to be at the pg/mL level for various compounds tested. Acceptable relative standard deviation (RSD) values (5.5-7.6%, n = 6) were obtained for direct measurement of analytes in complex matrixes; acceptable linear responses (0.1-50 ng/mL) and matrix effects (76.0-82.6%) were also found. Enhanced detection of compounds of interest in various real samples, such as food samples, human fluids, environmental water, and living organisms, was unambiguously demonstrated. Our experimental data showed that SPME-nESI-mMS is a promising tool for on-site analysis of various complex samples in significant applications including but not limited to food safety, environmental monitoring, forensic investigation, and bioanalysis.

A magnetic SERS-imprinted sensor for the determination of cardiac troponin I based on proteolytic peptide technology

Acute myocardial infarction is a sudden and high-mortality disease that can be accurately diagnosed by measuring the level of cardiac troponin I in the blood. Currently, cTnI commonly used clinical detection methods usually have excellent sensitivity and are suitable for large-scale sample detection analysis. However, most of these methods are operated through multiple steps of fixation, incubation, reaction and separation, and most of them require professionals to operate complex instruments, which greatly limits their applicability in real-time rapid detection. Therefore, a method that requires low professional skills and can perform rapid detection is necessary. We presents an alternative strategy to quantify cTnI in clinical serum samples using a combination of SERS and magnetic molecularly imprinted polymers (MMIP). MMIPs was synthesized under Polyvinyl Pyrrolidone (PVP) conditions without vinyl modification using characteristic peptide as template, MAA and DMAm as functional monomers. The internal Raman probe 4-MBA was connected through Ag-SH bonds in MMIPs to solve the problem that the target object had no Raman characteristic peak. MMIPs with high magnetic and adsorptive properties showed characteristic absorption peaks at the Raman shift of 1582 cm−1 after specific capture of the target templates. The Raman signals of the 4-MBA were reduced due to shielding effects and the detection range of this method was 0.001–100 ng mL−1. The recoveries and relative standard deviations (RSDs) of the spiked experiments were 103.1%–106.3 % and 3.54 %–7.38 %, respectively. In summary, this work had appropriate sensitivity and specificity, and there was no significant difference in detection results after ELISA verification. It provided a flexible and practical analysis method for detecting cTnI based on SERS technology. In addition, the imprinting materials of other disease markers can be prepared by changing the template molecules, which provides a new idea for the detection of other biomarkers.

Hydrogel-based fluorescence assay kit for simultaneous determination of ceftazidime and avibactam

Monitoring the concentration of antibiotics rapidly and cost-effectively is crucial for accurate clinical medication and timely identification of drug-induced illnesses. Here, we constructed a novel fluorescent assay kit to monitor Zavicefta, an effective antibiotic composed of avibactam (AVI) and ceftazidime (CFZ) to treat carbapenem-resistant gram-negative bacteria infections. AVI can emit fluorescence, but CFZ cannot. To enable simultaneous measurement of both in one kit, we designed molecularly imprinted polymer (MIP) modified quantum dots (QDs) for CFZ determination. MIPs have received significant attention as an artificial antibody due to their exceptional specificity for various targets, particularly drugs with small molecular weight. Under the excitation wavelength of 350 nm, the detection process involves a decrease in QDs’ fluorescence signal at 600 nm owing to the “gate effect” between MIP and CFZ and the internal filtration effect between CFZ and QDs. Simultaneously, a fluorescence emission characteristic peak at 420 nm for AVI emerges. In addition, to simplify the operation procedure and improve determination throughput, the detection agents were incorporated into a hydrogel and placed in a 96-well plate, enabling concurrent quantification of AVI and CFZ within the respective range of 80–1000 μM and 1–1000 μM. The developed assay kit successfully determined AVI and CFZ in human serums and therapeutic drug monitoring in a live rabbit model. Recoveries of AVI and CFZ were 92.7–114%, with relative standard deviations below 6.0%. Moreover, a smartphone was employed to read the fluorescence signals, which was beneficial for cost reduction and out-of-lab analysis. This study will deliver a pragmatic resolution to developing high-throughput assay kits for drug determination.Graphical

Unlocking the potential of eggplant peel: Powerful peroxidase nanozyme for l-cysteine determination in pharmaceutical supplements

For the first time, eggplant peel biowaste was upcycled through a very fast one-pot microwave synthesis to produce cost-effective and environmentally friendly blue-fluorescent carbon dots (EPE-CDs). The resulting EPE-CDs emitted fluorescence at 465 nm when excited at 400 nm and exhibited enhanced peroxidase-like behavior without metal doping requirement. They were able to oxidize o-phenylenediamine (OPD) in the presence of hydrogen peroxide (H2O2) to generate 2,3-diaminophenazine (DAP) leading to a new emission peak at 560 nm. Through the inner filter effect, DAP was able to quench the fluorescence of EPE-CDs, causing a change from colourless to yellow. By leveraging the fluorescence characteristics of EPE-CDs and DAP, dual-emission platform was established. This platform could be used for the catalytic detection of H2O2 within the 10–110 μM range. The introduction of L-Cysteine, containing reductive thiols that hinder DAP production, resulted in a reduction in the fluorescence intensity of DAP. The study demonstrated that fluorescence intensities ratio 465 nm / 560 nm (I465/I560) exhibited a linear relationship with L-Cysteine concentration between 4 and 60 μM, reaching detection limit as low as 0.69 μM. Furthermore, when applying the ratiometric fluorescence platform to quantify L-Cysteine in actual samples, the average recoveries ranged from 99.50 % to 101.40 %, with a relative standard deviation (RSD) not exceeding 2 %. Through the exploration of the fluorescence properties and nanozyme-like capabilities, this research offers a novel perspective on utilizing biowaste sources for CD synthesis and utilization of these CDs as nanozymes.

Two-group drift-flux model in tight lattice subchannel

Tight lattice rod bundles can increase equipment compactness and improve heat exchange efficiency, and they are widely adopted in heat exchange engineering. Understanding the flow characteristics of gas-liquid two-phase flow in tight lattice subchannels is essential for developing heat exchangers and fuel assemblies with these tight bundles. The drift-flux model (DFM) is a crucial two-phase flow model extensively used in subchannel analysis codes. Investigating the DFM in tight lattice subchannels benefits the advancement of these codes. For two-phase flow interfacial structures, significant two-group characteristics exist, with bubbles divided into small (group-one) and large (group-two) bubbles. The substantial differences in flow characteristics between these two groups provide a solid foundation for developing a two-group DFM. This study examined the two-group characteristics of two-phase flow in a tight lattice interior subchannel and developed a corresponding two-group DFM. The two-group correlations for the distribution parameters and drift velocities at the tight lattice interior subchannel level were proposed and verified using experimental data. The accuracy of the developed two-group DFM in predicting group-wise void fraction and gas velocity was also verified. The standard relative deviation between the model predictions and experimental data was 8.11 % and 13.1 % for group-one and group-two void fractions and 8.33 % and 11.7 % for group-one and group-two gas velocities, respectively. This indicates satisfactory accuracy for the newly developed two-group DFM in a tight lattice interior subchannel.

Development of an ionic liquid-based microextraction system (ILBME) for sensitive spectrophotometric analysis of neodymium(III) ions in environmental samples

ABSTRACT Introducing a precise, sensitive and simple system for determining neodymium(III) ions in aquatic samples could enhance the capabilities of routine instruments, particularly in terms of detection limits. Coupling a powerful preconcentration system, such as ionic liquid-based microextraction (ILBME), with a spectrophotometer can successfully achieve this goal. A sensitive and simple microextraction method based on a task-specific ionic liquid, designated [PDmim][Cl2], is described, in which the imidazolium-based ionic liquid served dual roles as both the chelating agent and the extraction phase. The ionic liquid was synthesized and characterized before being applied in microextraction procedure. The optimized microextraction results indicate that neodymium concentrations up to 5.10 µg L−1 can be successfully determined. The method characteristics, including the limit of detection (LOD), limit of quantification (LOQ), intra-day and inter-day relative standard deviations (RSDs), preconcentration factor (PF), enrichment factor (EF) and linear dynamic range (LDR), were found to be 1.53 µg L−1, 5.10 µg L−1, 3.83%, 4.44%, 123, 111.1 and 5.0–125.0 µg L−1, respectively. For method validation, the standard addition method using standard reference material (SRM) was employed, and the recovery range from real samples analyses was between 99.3% and 101.0%.

The Impact of Fat Contents and Different Cooking Processes on the Potential Health Concerns of Polycyclic Aromatic Hydrocarbons in Chicken Doner Kebabs

This study investigated the effects of different fat contents and cooking techniques on the presence of PAHs in chicken doner kebabs, as well as the dietary exposure and potential health risks for the Turkish population. The methodology for the detection and quantification of 16 PAH compounds in chicken doner samples using high-performance liquid chromatography (HPLC-UV) was validated. The limit of detection (LOD), quantification (LOQ), recovery, and relative standard deviation (RSD) were found to be 0.44%–1.14%, 1.45%–3.56%, 63.12%–101.50%, and 0.14%–3.16%, respectively. Our findings revealed that, among the analyzed compounds, BaA was the most dominant PAH compound, and that the charcoal cooking technique resulted in the highest accumulation of both BaP and PAH4 concentrations in chicken doner kebabs. Additionally, a significant increase in PAH levels was observed in relation to higher fat content. Moreover, it was found that the estimated daily intake (EDI) of BaP and PAH4 was higher in charcoal-grilled, well-done, high-fat chicken doner samples. As a result, the fact that the Margin of Exposure (MOE) values calculated for chicken doner samples across the Turkish population are above 10,000 indicates a low level of concern.

Investigating the metabolism of four sulfonamides in grass carp via HPLC-MS for screening candidate materials of matrix reference material

An efficient, sensitive, and precise method for investigating the metabolism of four sulfonamides in grass carp has been established using high-performance liquid chromatography-mass spectrometry. By optimizing the experimental conditions, the method achieved a coefficient of determination above 0.999, with detection and quantification limits set at 0.5 μg/kg and 1.0 μg/kg, respectively. Recovery rates were between 92.90 % and 102.84 %, and relative standard deviations ranged from 1.70 % to 9.83 %, enabling the precise detection of these sulfonamides in grass carp tissue. The factors affecting the metabolic rate during the medicated bath process were investigated, and obtained the optimal parameter conditions for screening the candidate materials. The candidate materials screened through this method exhibit good stability when used to prepare matrix standard substances, this work not only provides a scientific basis for screening sulfonamide candidate materials but also offers insights for developing other matrix reference materials.

Determination of trace uranium concentrations in spent‐fuel reprocessing using online graphite crystal pre‐diffraction energy‐dispersive x‐ray fluorescence

AbstractAn online graphite crystal pre‐diffraction x‐ray fluorescence technique was developed for accurate real‐time detection of trace uranium concentrations in spent‐fuel reprocessing streams. Online analysis for determining uranium concentrations was established. The device was equipped with measurement windows in both the flow cell and a side wall of the glove box. X‐ray tubes and detectors were arranged outside the glove box, and the process stream flowing through the flow cell was measured through the measurement window. A cylindrical highly oriented pyrolytic graphite crystal was located in front of the detector to improve detection efficiency and to provide monochromatic uranium‐characteristic x‐rays. At the same time, the device could perform remote online automatic calibration. The uranium detection limit in a kerosene solution was 0.08 mg/L, and the quantitative limit was 0.27 mg/L. The detection limit in a nitric acid solution was 0.11 mg/L, and the quantitative limit was 0.37 mg/L. The relative standard deviation of measuring 0.5 mg/L uranium was less than 10%, which greatly improved online monitoring of trace uranium in spent‐fuel reprocessing samples.

Validation of Neutrophil gelatinase-associated lipocalin (NGAL) for Diabetes-associated Acute Kidney Injury

Abstract Introduction/Objective This study aimed to evaluate the analytical and clinical performance of the BioPorto NGAL Test on the Beckman Coulter AU480 to correlate plasma neutrophil gelatinase-associated lipocalin levels (pNGAL) with clinical progression and severity of diabetes-associated acute kidney injury (AKI) with hospitalized patients at an East Central Georgia Medical Center Methods/Case Report Analytical validation of the BioPorto NGAL Test was carried out on the AU480 and was based on imprecision, limit of blank, limit of detection, functional sensitivity, carryover, and specificity. Clinical validation studies included 45 patients hospitalized between January and November 2023 with and without diabetes at risk for developing AKI. All patients’ pNGAL levels were measured at admission until 96 hours post admission. Receiver operating characteristics and likelihood ratio methods were used to determine optimal sensitivity, specificity, cutoff value, and the discriminatory power of pNGAL. Results (if a Case Study enter NA) The intra-assay and inter-assay imprecision percent relative standard deviation was between 0.8 (2.7%) and 3.7 (4.2%). The limit of blank and limit of detection of Bioporto NGAL was 2.2 ng/mL and 15.4 ng/mL, respectively. An analytical coefficient of variation of 20% corresponded to a pNGAL value of 9.9 ng/mL. The optimal cutoff value for pNGAL to predict AKI for patients with DM was 293 ng/mL, with a sensitivity of 80% and specificity of 87%; AUC: 0.85, p < 0.001. In a multivariate logistic regression model, pNGAL levels at 48 hours post admission were a risk factor for diabetes-associated AKI (OR 1.012, 95% CI:1.000 – 1.023; p = 0.051). Conclusion These results show that pNGAL levels at 48h are an independent risk factor for diabetes-associated AKI, and the optimal cutoff for this condition is 293 ng/mL. The optimal cutoff values for AKI for early diagnosis and risk stratification, along with its association with comorbidities, are important to improve patient outcomes and diagnosis accuracy.

A Liquid Chromatography‐Tandem Mass Spectrometry Bioanalytical Method Development and Validation for the Determination of Pacritinib in Plasma

ABSTRACTThe primary objective of the current work is to establish and verify an accurate and linear liquid chromatography‐electrospray ionization‐tandem mass spectrometry procedure for quantifying Pacritinib. An effective chromatographic resolution was obtained using the Hypersil Gold (50 × 4.6 mm, 2.1 µm) C18 column. The mobile phase is a mixture of methanol, 0.1% formic acid, and acetonitrile in the proportion of 20:15:65 (%v/v/v). The procedure involved closely monitoring executed ionic transitions of m/z 473.1/376.2 for Pacritinib and 584.26/101.1 for Brigatinib internal standard in multiple reaction monitoring mode. A strong correlation value (r2) of 0.9997 is associated with the linear plot regression line, which can be represented as y = 0.0001x − 0.0008. The relative standard deviation (RSD) results for the matrix effect were 3.63% and 3.57%, respectively, when the quality control (QC) level was low and high, respectively. Over the course of the study, the percentage average recoveries for Pacritinib were found to be 103.27% in high QC, 97.59% in medium QC, and 94.28% in low QC, respectively. The values that were obtained for the QC samples (0.378, 1.058, 7.56, and 11.34 µg/mL) varied from 2.00% to 4.03%. The developed method was useful for evaluating Pacritinib in biological samples for the purposes of QC, forensics, and bioavailability investigations for individuals.

Ultrasound-assisted rapid growth of chemically bonded bifunctional mesoporous covalent organic framework submicrospheres on a nickel-chromium alloy support for efficient solid-phase microextraction of bisphenols from water and milk samples

A layer-by-layer chemical bonding strategy was developed for fast in situ growth of bifunctional mesoporous covalent organic framework submicrospheres (COF SMSs) on the nickel-chromium alloy (Ni-Cr) fiber substrate via the ultrasound-assisted Schiff-base reaction for the first time. COF SMSs showed well-defined morphology, extraordinary high surface area (1211 m2·g−1) and narrow mesopore (2.50 nm) as well as excellent stability. Furthermore, the resulting Ni-Cr fiber presented outstanding adsorption capability and improved selectivity for bisphenols (BPs). Consequently, an attractive SPME-HPLC-UV approach with the Ni-Cr@Ni-Cr LDHs NSs@COF SMSs fiber was proposed for rapid preconcentration and sensitive determination of BPs. By optimizing adsorption parameters, the SPME-HPLC-UV method presented good linearity for five BPs in the ranges of 0.02–200 ng·mL−1 with coefficients of determination (R2) higher than 0.999. Limits of detection and limits of quantitation were obtained from 0.003 ng·mL−1 to 0.006 ng·mL−1 and from 0.010 to 0.019 ng·mL−1, respectively. Moreover, the intra-day and inter-day precision expressed as relative standard deviations (RSDs) was 1.57–3.52 % and 2.65–4.38 % for the proposed method with a single fiber, respectively. RSDs of the proposed method with different duplicate fibers were 3.25–6.72 %. The proposed SPME-HPLC-UV method was available for efficient preconcentration and sensitive detection of five BPs from real water and milk samples. The relative recoveries at three spiking levels of BPs were achieved in the range of 80.00–118.8 % with RSDs below 7.81 %. In addition, the prepared fiber still exhibited satisfactory adsorption performance after 120 adsorption-desorption cycles.