Semi-automated in vivo solid-phase microextraction sampling and the diffusion-based interface calibration model to determine the pharmacokinetics of methoxyfenoterol and fenoterol in rats

2012 ◽  
Vol 742 ◽  
pp. 37-44 ◽  
Author(s):  
Joanne Chung Yan Yeung ◽  
Inés de Lannoy ◽  
Brad Gien ◽  
Dajana Vuckovic ◽  
Yingbo Yang ◽  
...  
2012 ◽  
Vol 32 ◽  
pp. 31-39 ◽  
Author(s):  
Xu Zhang ◽  
Ken D. Oakes ◽  
Shuang Wang ◽  
Mark R. Servos ◽  
Shufen Cui ◽  
...  

2013 ◽  
Vol 125 (46) ◽  
pp. 12346-12348 ◽  
Author(s):  
Erasmus Cudjoe ◽  
Barbara Bojko ◽  
Inés de Lannoy ◽  
Victor Saldivia ◽  
Janusz Pawliszyn

2010 ◽  
Vol 93 (5) ◽  
pp. 1595-1599 ◽  
Author(s):  
Mohana Krishna Reddy Mudiam ◽  
Mahendra Pratap Singh ◽  
Debapratim Kar Chowdhuri ◽  
Ramesh Chandra Murthy

Abstract A simple, rapid, and solvent-free method for quantitative determination of benzene, toluene, and Xylene in exposed Drosophila larvae was developed using headspace solid-phase microextraction (HS-SPME) coupled to GC/MS. Larvae fed on standard Drosophila food mixed with benzene, toluene, and Xylene for 48 h were homogenized in Milli-Q water. Extraction of benzene, toluene, and Xylene was performed at 65C for 30 min on the SPME fiber (silica-fused). Subsequently, the fiber was desorbed in the GC injection port, followed by GC/MS analysis in the selected-ion monitoring mode. An external calibration curve was used for the quantification of benzene, toluene, and Xylene in the exposed organism. Recoveries were in the range of 78-82% (intraday) and 76-81% (interday) in larvae, and 9196 (intraday) and 87-92% (interday) in the diet. LOD with an S/N of 3:1 and LOQ with an S/N of 10:1 were in the range of 0.010.023 and 0.0340.077 µg/L, respectively. Percent RSD values for benzene, toluene, and Xylene were in the range of 0.500.81 (intraday) and 0.891.23 (interday) for retention time, and 2.163.85 (intraday) and 2.994.95 (interday) for peak concentration, showing good repeatability. This method was sensitive enough to quantitate benzene, toluene, and Xylene in small exposed organisms like Drosophila larvae. The SPME/GC/MS method developed may have wider applications in various in vivo toxicological studies.


Bioanalysis ◽  
2019 ◽  
Vol 11 (16) ◽  
pp. 1523-1534 ◽  
Author(s):  
Momna Aslam ◽  
Carlos Feleder ◽  
Ryan J Newsom ◽  
Serge Campeau ◽  
Florin Marcel Musteata

Aim: Solid-phase microextraction is proposed to measure concentrations of anandamide and 2-arachidonoyl glycerol in live rat brains in response to stress. Materials & methods: Solid-phase microextraction fibers were prepared from steel with 1.5 mm extraction coating. 24 male rats were divided into groups based on brain region, stria terminalis or posterior hypothalamus and loud noise or control groups. The fibers were desorbed in acetonitrile-water (75:25) and analyzed by ultraperformance LC–MS/MS. The linear range of the method was 0.05–50 ng/ml and the in vivo concentrations were found to be between 0.3 and 40 ng/ml. Conclusion: The new approach was successfully used to determine the concentrations of anandamide and 2-arachidonoyl glycerol in vivo and could be used in the future to measure other endogenous compounds.


Plant Disease ◽  
2014 ◽  
Vol 98 (8) ◽  
pp. 1088-1098 ◽  
Author(s):  
Rui Qiu ◽  
Dong Qu ◽  
Giles E. St. J. Hardy ◽  
Robert Trengove ◽  
Manjree Agarwal ◽  
...  

A robust technique was developed to identify Phytophthora cinnamomi using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography (GC) coupled to a flame ionization detector (FID) for analyzing volatile organic compounds (VOCs). Six fiber types were evaluated and results indicated that the three-phase fiber 50/30 μm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) had the highest extraction efficiency for both polar and nonpolar GC columns. The maximum extraction efficiency (equilibrium absorption) was achieved 16 h after fiber exposure in the HS. Absorbed compounds on the fiber were completely desorbed in the GC injector after 5 min at 250°C. Compared with the nonpolar column, the polar column showed optimum separation of VOCs released from P. cinnamomi. Under the optimized HS-SPME and GC/FID conditions, lower detection limits for the four external standards was found to be between 1.57 to 27.36 ng/liter. Relative standard deviations <9.010% showed that the method is precise and reliable. The method also showed good linearity for the concentration range that was analyzed using four standards, with regression coefficients between 0.989 and 0.995, and the sensitivity of the method was 104 times greater than that of the conventional HS method. In this study, the VOC profiles of six Phytophthora spp. and one Pythium sp. were characterized by the optimized HS-SPME-GC method. The combination of the VOCs creates a unique pattern for each pathogen; the chromatograms of different isolates of P. cinnamomi were the same and the specific VOC pattern of P. cinnamomi remained consistently independent of the growth medium used. The chromatograms and morphological studies showed that P. cinnamomi released specific VOCs at different stages of colony development. Using the optimized HS-SPME GC method, identification of P. cinnamomi from 15 in vivo diseased soil samples was as high as 100%. Results from this study demonstrate the feasibility of this method for identifying P. cinnamomi and the potential use of this method for physiological studies on P. cinnamomi.


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