• Analytical Science and Technology
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• v.30 no.6
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• pp.379-389
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• 2017

In this study, we set up an analytical method that can be used for rapid and accurate determination of representative isoquinoline alkaloids in medicinal plants using UPLC-ESI-Q-TOF MS (ultra pressure liquid chromatography-electrospray ionization-quadrupole-time-of-flight mass spectrometry). The compounds were eluted on a C18 column with 0.1 % formic acid and acetonitrile, and separated with good resolution within 13 min. Each of the separated components was characterized by precursor ions (generated by ESI-Q-TOF) and fragment ions (produced by collision-induced dissociation, CID), which were used as a reliable database. We also performed method validation: analytes showed excellent linearity ($R^2$, 0.9971-0.9996), LOD (5-25 ng/mL), LOQ (17-82 ng/mL), accuracy (91.6-97.4 %) as well as intra- and inter-day precisions (RSD, 1.8-3.2 %). In the analysis of Chelidonium majus L., magnoflorine, coptisine, sanguinarine, berberine and palmatine were detected by matching retention times and characteristic fragment ion patterns of reference standards. We also confirmed that, among the quantified components, coptisine was present in the highest quantity. Furthermore, alkaloid profiling was carried out by analyzing the fragment ion patterns corresponding to peaks of unknown components. In this manner, protopine, chelidonine, stylopine, dihydroberberine, canadine, and nitidine were tentatively identified. We also proposed the molecular structure of the fragment ions that appear in the mass spectrum. Therefore, we concluded that our suggested method for the determination of major isoquinoline alkaloids by UPLC-Q-TOF can be useful not only for quality control, but also for rapid and accurate investigation of phytochemical constituents of medicinal plants.

• Analytical Science and Technology
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• v.24 no.4
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• pp.266-274
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• 2011

Using a Hitachi LaChrom Ultra 2000U, a reverse phase ultra high performance liquid chromatography (u-HPLC) method was developed for the rapid quantification of 14 PAHs in foods. The proposed method for PAH analysis is based on solid phase extraction (SPE) cartridges; the determination was carried out by u-HPLC with fluorimetric detection. The method was very sensitive; PAH concentration levels were in a low ${\mu}g$/kg range and could be detected and quantified. Six samples of food were analyzed. Among PAHs, PHE was found in most of samples, the concentration ranging from 2.5 to 19.9 ${\mu}g$/kg. The contents of benzo[c]fluorine (BCL), pyrene (PYR), benzo[a]anthracene (BaA), chrysene (CHR), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF) were low at the '${\mu}g$/kg' level or were less than LOD.

• Advances in concrete construction
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• v.3 no.4
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• pp.295-316
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• 2015

A bridge widening technology using steel-concrete composite system was developed and is presented in this paper. The widened superstructure system consists of a newly built composite steel-concrete girder with concrete deck and steel diaphragms attached to the existing concrete girders. This method has been applied in several bridge widening projects in China, and one of those projects is presented in detail. Due to the higher stiffness-to-weight ratio and the rapid erection of composite girders, this widening method reveals benefits in both mechanical performance and construction. As only a few methods for the design of bridges with different types of girders are recommended in current design codes, a more accurate analytical method of estimating live load distribution on girder bridges was developed. In the analytical model, the effects of span length, girder pacing, diaphragms, concrete decks were considered, as well as the torsional and flexural stiffness of both composite box girders and concrete T girders. The study shows that the AASHTO LRFD specification procedures and the analytical models proposed in this paper closely approximate the live load distribution factors determined by finite element analysis. A parametric study was also conducted using the finite element method to evaluate the potential load carrying capacities of the existing concrete girders after widening.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.3
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• pp.237-242
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• 2014

Recently much research are has been done into the compositions of lead-free solders. As a result, there has been a rapid increase in the number of new compositions. In the past, the properties of these new compositions were determined and verified through drop-impact tests. However, these drop tests were expensive and it took a long time to obtain a result. The main goal of this study was to establish an analytical method capable of predicting the impact life-time of a new solder composition for board-level flip chips though the application of drop simulations using LS-DYNA. Based on the reaction load obtain with LS-DYNA, the drop-impact fracture cycles were predicted. The study was performed using a Sn-3.0Ag-0.5Cu solder (305 composition). To verify the reliability of the proposed analytical method, the results of the drop-impact tests and life-time analysis were compared, and were found to be in good agreement. Thus, the new analytical method was shown to be very useful and effective.

• Steel and Composite Structures
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• v.35 no.1
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• pp.29-41
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• 2020

Cross-beams of modern through truss bridges are connected to truss chord at its nodes and between them. It results in variable rotational end restraint for cross-beams, thus variable bending moment distribution. This feature is captured in three-dimensional modelling of through truss bridge structure. However, for preliminary design or rapid assessment of service load effects such technique of analysis may not be available. So an analytical method of assessment of rotational end restraint for cross-beam of through truss bridges was worked out. Two cases - nodal cross-beam and inter-nodal cross-beam - were analyzed. Flexural and torsional stiffness of truss members, flexural stiffness of deck members and axial stiffness of wind bracing members in the vicinity of the analyzed cross-beam were taken into account. The provision for reduced stiffness of the X-type wind bracing was made. Finally, general formula for assessment of rotational end restraint was given. Rotational end restraints for cross-beams of three railway through truss bridges were assessed basing on the analytical method and the finite element method (three-dimensional beam-element modelling). Results of both methods show good agreement. The analytical method is able to reflect effects of some structural irregularities. On the basis of the obtained results the general values of rotational end restraint for nodal and inter-nodal cross-beams of railway through truss bridges were suggested.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.423.1-423.1
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• 2002

A simple. specific and sensitive method for the determination of cyclosporine A (CsA) in human serum has been developed by a high performance liquid chromatography/diode array detector (DAD) and applied to pharmacokinetic study of CsA. This method involves the use of solid phase extraction procedure following rapid protein precipitation with zinc sulphate from 1 $m\ell$ of human serum, using a disposable $C_{18}$ extraction cartridge. (omitted)

• Analytical Science and Technology
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• v.8 no.3
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• pp.391-396
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• 1995

A rapid preconcentration method based on solvent extraction is described for the determination of gold by flame atomic absorption spectrophotometry. Trace amounts of gold was extracted as a new chelating agent, 3-thiophenaldehyde-4-phenyl-3-thiosemicarbazone from pH 4.0 in diisobutyl ketone. The method is simple, fast, free from the effect of many interfering ions and has a high sensitivity and a good precision. Gold is quantitatively separated and concentrated from the elements in standard sample, and the value of the recovery was 91.7 and 108.3% by the proposed method.

• Analytical Science and Technology
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• v.23 no.6
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• pp.615-618
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• 2010

An oxygen bomb combustion procedure were studied for determination of heavy metal in polymer materials such as polyvinyl chloride and polypropylene by ICP-AES. This method is proposed as a rapid and simple sample preparation for decomposition of polymer containing certified contents of the analytes by teflon coated oxygen bomb combustion using different absorbing solution. The recoveries of metal were found to be 30~102% from absorbed solution by ICP-AES method using polypropylene certified reference material(PP CRM-As, Ba, Cd, Hg, Pb, Zn). The recoveries of metal using PVC CRM(Cd, Hg, Pb) was found to be 45 ~101% with same procedures.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.415-419
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• 1994

A simple nad rapid colorimetric method for the assay of amodiaquine hydrochloride, chloroquine phosphate and primaquine phosphate is described. The method is based on the interaction of the drug base with bromophenol blue to give a ion-pair complex. The spectra of the complex shows a maxima at 415-420 nm with high apparent molar absorptivities. Beer's law was obeyed in the concentration range 1-8, 2-10 and $2-12{\;}{\mu}{\cdot}ml^{-1}$ for amodiaquine hydrochloride, primaquine phosphate and chloroquine phosphate respectively. The proposed method was applied to the determination of these drugs in certain formulations and the results were favourably comparable to the official methods.

• YAKHAK HOEJI
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• v.60 no.1
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• pp.15-20
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• 2016

Globotriaosylsphingosine (lyso Gb3) is considered as one of the biomarkers for Fabry disease. A rapid and simple UPLC-MS/MS method was developed for the determination of reliable biomarker, lyso Gb3. Total analytical procedure takes only 15 min including sample preparation and MS/MS analysis. Limit of detection was 0.85 ng/ml (S/N=3). The calibration curve was linear over the range of 2.0~400.0 ng/ml ($R^2=0.9999$). Inter-day and intra-day assay accuracy were 93.4~100.6% (RSD, 0.6~6.0%) and 97.5~100.7% (RSD, 3.6~5.2%). Absolute recoveries of 97.6~98.6 showed excellence of a new analytical method. The method was applied to human and mice urines, proved the suitability for the quantification of lyso-Gb3 for screening, diagnosis and therapeutic monitoring of Fabry disease patients.