Development of molecularly imprinted Acrylamide-Acrylamido phenylboronic acid copolymer microbeads for selective glycosaminoglycan separation in children urine

2019 ◽  
Vol 44 (6) ◽  
pp. 738-744 ◽  
Author(s):  
Zihni Onur Uygun ◽  
Burcu Okutucu ◽  
Şükriye Hacikara ◽  
Ferhan Sağın
Keyword(s):  
Liquid Chromatography ◽  
Chondroitin Sulfate ◽  
Matrix Effect ◽  
Boronic Acid ◽  
Dermatan Sulfate ◽  
Binding Capacity ◽  
Phenylboronic Acid ◽  
Molecularly Imprinted ◽  
Acid Copolymer ◽  
Chromatography Columns

Abstract Background In this study, we synthesized molecularly imprinted copolymers for liquid chromatography columns as a separator for glycosaminoglycan (dermatan sulfate; DS and chondroitin sulfate; CS) in urine. Materials and methods Acrylamide and acrylamido phenylboronic acid were used as monomers, acrylamide was used for as base monomer to attract negatively charged groups and acrylamido phenylboronic acid (AAPBA) residues used to form diol bonds between sugar and boronic acid residues to strengthen the attraction. These monomers were synthesized by using precipitation polymerization to form uniform spheres, which are more durable for the pressurized chromatographic systems. Trimethylolpropane trimethacrylate and AIBN were used as crosslinker and starter, respectively. Results These GAG selective polymers were filled by pressurized flow into the steel (4.6 mm × 1.6 mm) columns, then imprinted GAGs were extracted and analyzed to calculate binding capacity of each milligram polymer. Calibration curves of the GAG selective columns were obtained 62.5–1000 ng/mL less than 5% coefficient variation, and lower matrix effect. Conclusion Our imprinted columns separated different GAGs from urine specifically and sensitively. Matrix effect was at an ignorable level thus the challenging use.

scholarly journals Microextraction by Packed Molecularly Imprinted Polymer Combined Ultra-High-Performance Liquid Chromatography for the Determination of Levofloxacin in Human Plasma

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Jia Meng ◽  
Xu Wang
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Human Plasma ◽  
Bacterial Infections ◽  
High Performance ◽  
Limit Of Detection ◽  
Binding Capacity ◽  
Molecularly Imprinted ◽  
Relative Standard

Fluoroquinolones are considered as gold standard for the prevention of bacterial infections. To improve assessment of antibacterial efficacy, a novel method for determination of levofloxacin was developed and validated. Deep eutectic solvents (DESs) as only green solvent were used as a porogen for preparation of water-compatible molecularly imprinted polymers (MIPs) with a pseudotemplate. The DESs-MIPs were characterized in detail, including scanning electron microscope, nitrogen sorption porosimetry, and Fourier transform-infrared spectra. Clearly, the maximum binding capacity of levofloxacin on DESs-MIPs in water and methanol was 0.216 and 0.077 μmol g−1, respectively. The DESs-MIPs as adsorbing materials were applied in microextraction by packed sorbent (MEPS), and the DESs-MIPs-MEPS conditions were optimized. The DESs-MIPs-MEPS coupled with ultra-high-performance liquid chromatography (UHPLC) was used to determine levofloxacin in human plasma. The method was found linear over 0.05–10 μg mL−1 with coefficient of correlation equal to 0.9988. The limit of detection and limit of quantification were 0.012 and 0.04 μg mL−1, respectively. At three spiked levels, the precision of proposed method was between 95.3% and 99.7% with intraday and interday relative standard deviations ≤8.9%. Finally, the developed method was used to examine levofloxacin from human plasma of 20 hospitalized patients after transrectal ultrasound-guided prostate biopsy, and the average concentration (±SD) of levofloxacin was 2.35 ± 0.99 μg mL−1 in plasma.

Rapid evaluation method for propofol abusing with hair by using centrifugal filter and liquid chromatography-tandem mass spectrometry

2020 ◽  
Vol 16 ◽  
Author(s):  
Jaesung Pyo
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Matrix Effect ◽  
Hair Sample ◽  
Extraction Procedure ◽  
The Body ◽  
Tandem Mass ◽  
Centrifugal Filter ◽  
Hair Samples

Background: Since propofol is rapidly metabolized and excreted from the body, it is not easy to quantify its intake in blood or urine sample over the time. In this case, the hair sample would be more advantageous to estimate during the abuse period. However, presence of protein and lipid in the hair sample could interfere extraction and be problematic during mass spectrometric analysis. Objective: The aim of this study is to develop the simple and less-time consuming method for extraction of propofol glucuronide by removing hair interferences with centrifugal filter. Method: Hair samples were washed and dissolved with sodiumhydroxide solution. This dissolved hair solution was applied to centrifugal filter and centrifuged. The filtrate was extracted with ethyl acetate and evaporated to dryness. The residue was reconstituted with methanol and analyzed by liquid chromatography coupled with tandem mass spectrometry. This developed analytical method was validated by testing of linearity, selectivity, accuracy, precision, recovery, matrix effect and stability of propofol glucuronide. Results and Discussion: The validation results showed good linearity over the concentration range of 0.5~500 pg/mg, with correlation coefficient of 0.9991. The LOD and LLOQ was 0.2 and 0.5 pg/mg, respectively. The intra-and inter-day precision and accuracy were acceptable within 14.5% for precision and 10.1% for accuracy. Similarly, the developed method revealed high sample recovery (>88%), low hair matrix effect (<10%) and highly-efficient extraction procedure. Conclusion: This well validated procedure was successfully applied to determine propofol glucuronide in rat hair sample and can be applicable, with high potential, in the field of forensic toxicology especially with increasing abuse and accidental overdose of propofol.

Sign in / Sign up

Export Citation Format

Share Document