scholarly journals High-Throughput UHPLC-MS/MS Measurement of Per- and Poly-Fluorinated Alkyl Substances in Human Serum

2020 ◽  
Vol 44 (4) ◽  
pp. 339-347 ◽  
Author(s):  
M Abdul Mottaleb ◽  
Michael C Petriello ◽  
Andrew J Morris
Keyword(s):  
Human Serum ◽  
High Throughput ◽  
Food Packaging ◽  
Limit Of Detection ◽  
Epidemiological Studies ◽  
Ultra Performance Liquid Chromatography ◽  
Synthetic Surfactant ◽  
University Of Kentucky ◽  
Relative Standard ◽  
Almost All

Abstract Per- and poly-fluorinated alkyl substances (PFASs) are a large group of synthetic surfactant chemicals with widespread uses in food packaging and textile manufacturing and as the main constituent of aqueous film-forming firefighting foams. PFASs are highly persistent in the environment, and human exposures are extensive with these chemicals detectable in the blood of almost all adult Americans. PFASs exhibit a range of toxic effects in preclinical models. In humans, PFAS exposure has been associated with lower birth weights, decreased immune responses, cancer and impaired fertility and elevated circulating cholesterol levels. We have developed a sensitive high-throughput method for quantification of representative PFAS in human serum and plasma for biomonitoring and epidemiological studies of human health effects of PFAS exposure. The method combines robust and reproducible 96-well plate format sample preparation with ultra-performance liquid chromatography–tandem mass spectrometry. The method was developed, validated and used for targeted measurements of eight short-/long-chain PFAS analytes in human serum. Targeted analytes were measured in 50 microliters of sample using mass-labeled internal standards. Mean spiked recoveries (n = 10) of target analytes for three tiers quality control (QC-low, QC-medium, QC-high) samples ranged from 70 to 127% with 2–14% relative standard deviation (RSD). The average spiked recoveries (n = 10) of surrogates were 79–115% with 8–12% RSD for QC-low, 90–123% with 7–12% RSD for QC-medium and 82–114% with 9–15% RSD for QC-high. The limit of detection for the target compounds was 0.05–0.04 ng/mL. The method was used to reveal regional differences in PFAS exposures in Kentucky residents receiving care at the University of Kentucky Hospitals.

scholarly journals Determination of Trace Zearalenone and Its Metabolites in Human Serum by a High-Throughput UPLC-MS/MS Analysis

2019 ◽  
Vol 9 (4) ◽  
pp. 741 ◽  
Author(s):  
Danlei Sun ◽  
Chenglong Li ◽  
Shuang Zhou ◽  
Yunfeng Zhao ◽  
Yun Gong ◽  
...  
Keyword(s):  
Human Serum ◽  
High Throughput ◽  
Solid Phase ◽  
Internal Standard ◽  
Ultra Performance Liquid Chromatography ◽  
Enzyme Hydrolysis ◽  
Serum Samples ◽  
Relative Standard ◽  
Before And After

This paper described an improved method for high-throughput and sensitive determination of zearalenone and its five metabolites (zearalanone, α-zearalenol, β-zearalenol, α-zearalanol and β-zearalanol) in human serum. Serum samples were measured both before and after enzyme hydrolysis to assess the free and total amount of each compound by ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) in multi reaction monitoring (MRM) mode following off-line 96-well μElution solid-phase extraction (SPE). All the analytes were completely separated on a C18 column within 6 min. It enabled multi-sample preparation at the same time eliminating tedious evaporation and reconstitution steps, allowing 96 (one plate) samples to be processed and analyzed within 24 h. Using an isotope labelled internal standard (13C-ZEN), high recoveries were achieved for all the compounds in the range 91.6%–119.5%, with intra-day and inter-day relative standard deviations (RSDs) of less than 8%. The limits of detection (LOD) and the limits of quantification (LOQ) were 0.02–0.06 ng mL−1 (0.6–2 fmol) and 0.1–0.2 ng mL−1 (3–6 fmol), respectively, demonstrating a notable enhancement in sensitivity compared to the existing methods. The validated method was applied to the analysis of paired urine and serum samples collected from 125 healthy individuals in Henan Province, locating in the middle area of China. ZEN metabolites in human serum were significantly lower than those in urine. Only one serum sample was positive for ZEN after enzyme digestion, whereas at least one of ZEN biomarkers was detected in 75.2% of the paired urine samples. Some comparison and discussion were also included in this paper.

Calcium/Copper alginate framework doped with CuO nano-particles as a novel adsorbent for micro-extraction of benzodiazepines from human serum

2020 ◽  
Vol 16 ◽  
Author(s):  
Nadereh Rahbar ◽  
Fatemeh Ahmadi ◽  
Zahra Ramezani ◽  
Masoumeh Nourani
Keyword(s):  
Human Serum ◽  
High Performance ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Nano Particles ◽  
Limit Of Quantification ◽  
Analytical Methodology ◽  
Fiber Fabrication ◽  
Relative Standard ◽  
Green Procedure

Background: Sample preparation is one of the most challenging phases in pharmaceutical analysis, especially in biological matrices, affecting the whole analytical methodology. Objective: In this study, a new Ca(II)/Cu(II)/alginate/CuO nanoparticles hydrogel fiber (CCACHF) was synthesized through a simple, green procedure and applied for fiber micro solid phase extraction (FMSPE) of diazepam (DIZ) and oxazepam (OXZ) as model drugs prior to high-performance liquid chromatography-UV detection (HPLC-UV). Methods: Composition and morphology of the prepared fiber were characterized and the effect of main parameters on the fiber fabrication and extraction efficiency have been studied and optimized. Results: In optimal conditions, calibration curves were linear ranging between 0.1–500 µg L−1 with regression coefficients of 0.9938 and 0.9968. Limit of detection (LOD) (S/N=3) and limit of quantification (LOQ) (S/N=10) of the technique for DIZ and OXZ were 0.03 to 0.1 µg L−1. Within-day and between-day relative standard deviations (RSDs) for DIZ and OXZ were 6.0–12.5% and 3.3–9.4%, respectively. Conclusion: The fabricated adsorbent has been substantially employed to extraction of selected benzo-diazepines (BZDs) from human serum real specimens and the obtained recoveries were also satisfactory (82.1-109.7%).

Square-wave cathodic adsorptive stripping voltammetry of risperidone

2011 ◽  
Vol 76 (3) ◽  
pp. 159-176 ◽  
Author(s):  
Ibrahim Hüdai Taşdemir ◽  
Orhan Çakirer ◽  
Nevin Erk ◽  
Esma Kiliç
Keyword(s):  
Human Serum ◽  
Human Urine ◽  
Limit Of Detection ◽  
Direct Determination ◽  
Reduction Wave ◽  
Pharmaceutical Dosage Forms ◽  
Peak Current ◽  
Square Wave ◽  
Relative Standard ◽  
Spiked Human Urine

Electrochemical properties and diffusion-adsorption behavior of risperidone (RPN), an antiphyscotic drug, on hanging mercury drop electrode (HMDE) were carried out in Britton–Robinson (BR) buffer. Some electrochemical parameters such as diffusion coefficient, number of transferred electrons and proton participated to its reduction mechanism and surface coverage coefficient were calculated from the results of cyclic voltammetry, square-wave voltammetry and constant potential electrolysis. RPN was found to be reduced with single two-electron/two-proton quasi-reversible mechanism controlled mainly by adsorption with some diffusion contribution at the potential about –1.58 V (vs Ag|AgCl electrode). Experimental parameters were optimized to develop a new, accurate, rapid, selective and simple square-wave cathodic adsorptive stripping voltammetric (SWCAdSV) method for direct determination of RPN in pharmaceutical dosage forms, spiked human urine and human serum samples without time-consuming steps prior to drug assay. This method was based on the relation between the peak current and the concentration of RPN and it was recognized that peak current of reduction wave linearly changes with the concentration of RPN in the concentration range of 1.5–150 nM, when optimum preconcentration potential –0.65 V and optimum preconcentration time 60 s were applied. In this method, limit of detection (LOD) was found as 5.18 nM (2.12 ppb). The method was successfully applied to determine the RPN content of commercial pharmaceutical preparations, spiked human serum and spiked human urine. The method was found to be highly accurate and precise, having a relative standard deviation of less than 4.80% for all applications.

scholarly journals Determination of uric acid in human serum by an enzymatic method using N-methyl-N-(4-aminophenyl)-3-methoxyaniline reagent

2003 ◽  
Vol 68 (8-9) ◽  
pp. 691-698 ◽  
Author(s):  
Milena Jelikic-Stankov ◽  
Predrag Djurdjevic ◽  
Dejan Stankov
Keyword(s):  
Uric Acid ◽  
Human Serum ◽  
Limit Of Detection ◽  
Ascorbate Oxidase ◽  
Acid Oxidation ◽  
Uric Acid Concentration ◽  
Enzymatic Method ◽  
Limit Of Quantification ◽  
Relative Standard

In this work a new enzymatic method for the determination of uric acid in human serum has been developed. The method is based on the oxidative coupling reaction between the N-methyl-N-(4-aminophenyl)-3-methoxyaniline (NCP) reagent and the hydrogen ? donor reagent N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline (TOOS), in the system involving three enzymes: uricase, peroxidase and ascorbate oxidase. Using this method uric acid could be determined in concentrations up to 1.428 mmol/L, with a relative standard deviation of up to 1.8 %. The effect of the medium pH and the NCP concentration on the linearity of the chromogen absorbance versus the uric acid concentration curve was investigated. The influence of the uricase activity on the maximum rate of uric acid oxidation was also examined. The use of the NCP reagent demonstrated a more precise and more sensitive determination of the uric acid compared to the determination with 4-aminoantipyrine (4-AA) as the coupling regent. The sensitivity of the method determined from the calibration curve was 0.71 absorbance units per mmol/L of uric acid; the limit of detection was LOD = 0.0035 mmol/L and the limit of quantification was LOQ = 0.015 mmol/L of uric acid.

scholarly journals Determination of Picogram Levels of Roxithromycin in Pharmaceutical, Human Serum, and Urine by Flow-Injection Chemiluminescence

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Jiangman Liu ◽  
Huan Yang ◽  
Yun Zhang ◽  
Min Wu ◽  
Haixiang Zhao ◽  
...  
Keyword(s):  
Human Serum ◽  
Flow Injection ◽  
Limit Of Detection ◽  
Inhibitory Effect ◽  
Injection System ◽  
Relative Standard ◽  
Flow Injection System ◽  
Flow Injection Chemiluminescence ◽  
Serum And Urine

A sensitive chemiluminescence (CL) method, based on the inhibitory effect of roxithromycin (ROX) on the CL reaction between luminol and dissolved oxygen in a flow-injection system, was first proposed for the determination of ROX at picogram levels. The decrement of CL intensity was linearly proportional to the logarithm of ROX concentrations ranging from 0.1 to 100 pg mL-1, giving the limit of detection (LOD) of 0.03 pg mL-1 (3σ). At a flow rate of 2.0 mL min-1, a complete analytical procedure including sampling and washing could be performed within 0.5 min, with relative standard deviations (RSDs) of less than 5.0% (n=5). The proposed procedure was applied successfully to the determination of ROX in pharmaceutical, human serum, and urine with the recoveries ranging from 90.0 to 110.0%.

scholarly journals Method Development and Validation for Simultaneous Quantification of Microcystin Congeners in Water

2021 ◽  
Author(s):  
Xiaocui Qiao ◽  
Simin Ge ◽  
Chengyou Liu ◽  
Lixin Jiao ◽  
Xue Li ◽  
...  
Keyword(s):  
Formic Acid ◽  
Method Development ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Signal To Noise Ratio ◽  
Internal Standard ◽  
Ultra Performance Liquid Chromatography ◽  
Chaohu Lake ◽  
Online Spe ◽  
Relative Standard

Abstract Background: Microcystins, as secondary metabolites of cyanobacteria, are hepatotoxic to humans through the ingestion of cyanobacteria-contaminated water. Microcystins with diverse congeners in water can be precisely quantified using online solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (online-SPE UPLC-MS/MS). A method was developed and validated to simultaneously quantify eight microcystin congeners in water using online-SPE UPLC-MS/MS.Results: The method achieved the highest efficiency and sensitivity by selecting acetonitrile with 0.1% formic acid and water with 0.1% formic acid as the best mobile phase conditions. Linearity, accuracy, and precision were validated on matrix-mixed water with the leucine enkephalin internal standard. The limit of detection calculated using the signal-to-noise ratio of 3 passed the surface water daily inspection for microcystins. Except for the lower recovery of individual substances at individual concentrations, the recoveries of the remaining microcystin congeners ranged from 70 to 130%, and the relative standard deviation was less than 10%.Conclusion: The method was used to analyze microcystins in 12 water samples collected from Chaohu Lake. The sum of all microcystin congeners ranged from 101 to 585 ng L-1 in water (<WHO drinking water safe limit of 1 μg L-1 for microcystin-LR).

scholarly journals Electrochemical Immunosensor for the Early Detection of Rheumatoid Arthritis Biomarker: Anti-Cyclic Citrullinated Peptide Antibody in Human Serum Based on Avidin-Biotin System

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 124
Author(s):  
Somasekhar R. Chinnadayyala ◽  
Sungbo Cho
Keyword(s):  
Rheumatoid Arthritis ◽  
Human Serum ◽  
Microelectrode Array ◽  
Microelectromechanical Systems ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Transfer Resistance ◽  
Relative Standard ◽  
Modified Ice ◽  
Hands And Feet

Rheumatoid arthritis (RA) is a chronic autoimmune disease that produces a progressive inflammatory response that leads to severe pain, swelling, and stiffness in the joints of hands and feet, followed by irreversible damage of the joints. The authors developed a miniaturized, label-free electrochemical impedimetric immunosensor for the sensitive and direct detection of arthritis Anti-CCP-ab biomarker. An interdigitated-chain-shaped microelectrode array (ICE) was fabricated by taking the advantage of microelectromechanical systems. The fabricated ICE was modified with a self-assembled monolayer (SAM) of Mercaptohexanoic acid (MHA) for immobilization of the synthetic peptide bio-receptor (B-CCP). The B-CCP was attached onto the surface of SAM modified ICE through a strong avidin-biotin bio-recognition system. The modified ICE surface with the SAM and bio-molecules (Avidin, B-CCP, Anti-CCP-ab and BSA) was morphologically and electrochemically characterized. The change in the sensor signal upon analyte binding on the electrode surface was probed through the electrochemical impedance spectroscopy (EIS) property of charge-transfer resistance (Rct) of the modified electrodes. EIS measurements were target specific and the sensor response was linearly increased with step wise increase in target analyte (Anti-CCP-ab) concentrations. The developed sensor showed a linear range for the addition of Anti-CCP-ab between 1 IU mL−1 → 800 IU mL−1 in phosphate buffered saline (PBS) and Human serum (HS), respectively. The sensor showed a limit of detection of 0.60 IU mL−1 and 0.82 IU mL−1 in the PBS and HS, respectively. The develop bio-electrode showed a good reproducibility (relative standard deviation (RSD), 1.52%), selectivity and stability (1.5% lost at the end of 20th day) with an acceptable recovery rate (98.0% → 101.18%) and % RSD’s for the detection of Anti-CCP-ab in spiked HS samples.

Highly Sensitive Detection of miRNA-155 Using Molecular Beacon-Functionalized Monolayer MoS2 Nanosheet Probes with Duplex-Specific Nuclease-Mediated Signal Amplification

2021 ◽  
Vol 17 (6) ◽  
pp. 1034-1043
Author(s):  
Ying Liu ◽  
Zhou Ding ◽  
Jingjing Zhang ◽  
Chunyuan Song ◽  
Le Zhang ◽  
...  
Keyword(s):  
Human Serum ◽  
Fluorescent Probe ◽  
Molecular Beacon ◽  
Limit Of Detection ◽  
Fluorescence Signal ◽  
Linear Calibration ◽  
Highly Sensitive ◽  
Relative Standard ◽  
Highly Sensitive Detection ◽  
Fluorescence Amplification

MicroRNA-155 (miRNA-155) as a characteristic myeloma-associated biomarker exhibits significant potential application in the diagnosis of multiple myeloma (MM). In this paper, a novel type of molecular beacon (MB)-functionalized monolayer MoS2 nanosheet probe was proposed as fluorescent probe for high-sensitive assays of miRNA-155that uses a duplexspecificnuclease (DSN) enzyme to amplify the fluorescence signal. The preparation and detection conditions of the fluorescent probes were optimized in some aspects, such as the concentration of MoS2 (0.80 μM) and DSN (0.2 U), and the incubation time of DSN (30 min). The probesexhibited a sensitive fluorescence response to miRNA-155 and the fluorescence signal of the assay was significantly amplified by the cleavage of DSN. The relationship between F/F0 and logC miRNA follows a linear calibration curve, and the limit of detection (LOD) of miRNA-155 in 10% human serum is calculated to be 10.96 fM based on this relationship. The good performance and fluorescence amplification effect of the fluorescent probe were confirmed by studying the recovery of miRNA-155 in 10% human serum, which was ranged from 98.32% to 106.3% with a relative standard deviation of less than 4.14%. Besides, the high expression of miRNA-155 in clinic blood of MM patients was sensitively distinguished from healthy peoples by using the proposed probes. The proposed novel fluorescent probe based on the DSN can be used to detect miRNA-155 in human serum and provide a potential, convenient and reliable tool for diagnosis of MM.

scholarly journals Determination of cholesterol in human serum by an enzymatic method with the application of daos reagent

2000 ◽  
Vol 65 (7) ◽  
pp. 473-479
Author(s):  
Milena Jelikic-Stankov ◽  
Dejan Stankov ◽  
Snezana Paunovic
Keyword(s):  
Clinical Practice ◽  
Human Serum ◽  
Free Cholesterol ◽  
Limit Of Detection ◽  
Enzymatic Method ◽  
Limit Of Quantification ◽  
Experimental Conditions ◽  
Relative Standard ◽  
Influence Of Ph

A sensitive and specific enzymatic method has been developed for the determination of the total and free cholesterol in human serum based on the application of the newly-synthesized N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline, (DAOS) Trinder's reagent. Using the proposed method, cholesterol could be determined in the concentration range of 0.15 mmol/L with a relative standard deviation of up to 1.1%. In order to find the optimal experimental conditions for the application of the DAOS reagent, the influence of its concentration on the linearity of the method, the influence of pH, as well as the influence of the activities of cholesterolesterase and cholesteroloxidase were examined. The obtained results of the determination of the total and free cholesterol were compared to the results obtained by the application of the most frequently employed enzymatic method in clinical practice, based on phenol as a reagent. The sensitivity of the method was 0.070 A/mmol/L, the limit of detection DL=0.03 mmol/L and the limit of quantification QL=0.09 mmol/L of cholesterol.

A MASS COMPATIBLE UPLC METHOD FOR THE QUANTIFICATION OF IMPURITIES IN FLUTICASONE PROPIONATE NASAL SPRAY

2020 ◽  
pp. 80-87
Author(s):  
MUGADA RAVI PRASADA RAO ◽  
RAMA KRISHNA THOTA ◽  
MAHIBALAN SENTHI ◽  
PAUL MOGADATI ◽  
SRINIVAS ARUTLA
Keyword(s):  
Fluticasone Propionate ◽  
Nasal Spray ◽  
Limit Of Detection ◽  
Glass Container ◽  
Ultra Performance Liquid Chromatography ◽  
Compatibility Study ◽  
Limit Of Quantification ◽  
Water As Solvent ◽  
Relative Standard ◽  
Container Closure

Objective: The objectives of the present study were to develop and validate a mass compatible ultra-performance liquid chromatography (UPLC) method to quantify the impurities in fluticasone nasal spray, and to establish a suitable container-closure system for the formulation. Methods: A gradient method was optimized with a flow rate of 0.5 ml/min, detector wavelength-240 nm, run time-25 min and 0.1% Trifluoroacetic acid (TFA) in water as solvent A and Methanol as solvent B. Results: The developed method was linear over the range of 0.07-1.10 µg/ml for impurity-I, 0.16-2.47 µg/ml for impurity-II, 0.67-10.0 µg/ml for impurity-III, and 1.29-19.3 µg/ml for impurity-IV. The limit of quantification (LOQ) and limit of detection (LOD) were established as 0.07 and 0.02 µg/ml, 0.14 and 0.05 µg/ml, 0.59 and 0.19 µg/ml, 1.06 and 0.35 µg/ml for impurities I-IV respectively. The percent relative standard deviation (%RSD) of the replicate analysis for impurities I-IV, was within the acceptance criteria (0.4, 0.2, 0.3, and 0.1% respectively) that proved the precision of the method. The accuracy of the method was studied from 50%-150% of test concentration and the results ranged from 100.3% to 109.4%. The container-closure compatibility study revealed that the solution stored in the glass container system did not generate any additional peaks in the chromatogram. Conclusion: Hence, the developed method can be employed by quality testing laboratories to quantify impurities in fluticasone propionate nasal spray. The study also suggests that glass containers could serve as a compatible system for the storage of fluticasone propionate nasal solution.

Sign in / Sign up

Export Citation Format

Share Document