Determination of d ‐limonene in mice plasma and tissues by a new GC–MS/MS method: Comparison of the pharmacokinetics and tissue distribution by oral and inhalation administration in mice

2019 ◽  
Vol 33 (7) ◽  
pp. e4530 ◽  
Author(s):  
Chen Chen ◽  
Yunhua Sheng ◽  
Yue Hu ◽  
Jie Sun ◽  
Wei Li ◽  
...  
Keyword(s):  
Tissue Distribution ◽  
Method Comparison ◽  
Inhalation Administration

scholarly journals Determination of Equivalent Mohr-Coulomb Criterion from Generalised Hoek-Brown Criterion

2021 ◽  
Author(s):  
Qingqing Yang ◽  
Fei Cai
Keyword(s):  
Principal Stress ◽  
Least Squares Method ◽  
Method Comparison ◽  
Friction Angle ◽  
Engineering Practice ◽  
Shear Strength Parameters ◽  
Strength Parameters ◽  
Coulomb Criterion ◽  
Minor Principal Stress

Abstract A new analytical solution is presented for determining equivalent Mohr-Coulomb (MC) shear strength parameters over an arbitrary interval of minor principal stress σ3 from the generalised Hoek-Brown (HB) criterion using least squares method. Comparison with several published examples demonstrates that the proposed solution had a capacity to accurately determine equivalent MC parameters over a given interval of σ3, as well as instantaneous MC parameters by using a very small interval of σ3. EMC parameters depended heavily on the interval of σ3, which highlighted the importance of intervals of σ3. A calculation case shows that the equivalent internal friction angle and cohesion over the interval of σ3 from tension cut-off σcut−off to maximum minor principal stress σ3max were approximately 12% smaller and 10.3% larger than those over an interval from tensile strength to σ3max, respectively. The proposed solution offers great flexibility for the application of the HB criterion with existing methods based on the MC criterion for rock engineering practice.

scholarly journals Direct Determination of Free Methionine in Soy-Based Infant Formula

2004 ◽  
Vol 87 (1) ◽  
pp. 123-128
Author(s):  
Paul Johns ◽  
Rosalyn Phillips ◽  
Lobat Dowlat
Keyword(s):  
Infant Formula ◽  
Mobile Phase ◽  
Method Comparison ◽  
Water System ◽  
Direct Determination ◽  
Reversed Phase ◽  
Intermediate Precision ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract A method was developed for the direct determination of free methionine in soy-based infant formula, with analyte separation and quantitation by reversed-phase liquid chromatography (LC), and UV absorbance at 214 nm, respectively. Sample preparation required only dilution with mobile phase and syringe filtration. Using a 0.02M KH 2 PO 4 mobile phase (pH adjusted to 2.9 with 85% o-phosphoric acid) and 0.7 mL/min flow rate, methionine eluted at approximately 8 min, and total run time was 14 min after column regeneration with acetonitrile–water. System linearity was demonstrated as peak area versus analyte concentration, ranging from 80 to 120% of the formula specification for free methionine (r > 0.999, and all residuals <0.45%). Intermediate precision relative standard deviation values were <1.5% for ready-to-feed and reconstituted powder samples, and recoveries ranged from 98.0 to 103.5% for inter-method comparison with an amino acid analyzer method. The limit of quantitation was 3 mg methionine/L in the “as fed” infant formula. Despite the relatively weak UV absorptivity of methionine, the 214 nm signal was sufficiently intense in the 30–65 mg/L (201–436 μM) range to afford quantitation by peak area proportionation versus a 2-point external standard calibration. This direct UV detection after reversed-phase LC separation provides a simple and accurate method for determining free methionine without derivatization.

Immuno-affinity columns versus conventional clean-up: a method-comparison study for the determination of zearalenone in corn

1998 ◽  
Vol 360 (2) ◽  
pp. 241-245 ◽  
Author(s):  
R. Schuhmacher ◽  
R. Krska ◽  
M. Grasserbauer ◽  
W. Edinger ◽  
H. Lew
Keyword(s):  
Method Comparison ◽  
Comparison Study ◽  
Method Comparison Study
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