These results illustrate that the SPARC CL system provides an excellent platform to quickly reveal zonation patterns in such minerals and that it can also be used as an effective screening tool for ad
This application note presents a step-by-step method for release, labeling, separation, and exoglycosidase-based structural elucidation of N-glycans from human serum IgG and commercial chimeric IgG1 mAb (infliximab) using Thermo Scientific™ Vanquish™ Horizon UHPLC-FLD and confirmation of the structures by a Thermo Scientific™ Q Exactive™ Plus Hybrid Quadrupole-Orbitrap™ mass spectrometer.
Combining the resolving capability of IC with the detection power of ICP-MS allows fast, easy and reliable analysis of bromine species in drinking waters. Low background and He-KED interference removal permit robust conditions so that sample preparation is virtually eliminated and analysis of the water can be performed from the tap to the vial after simple alkalinization. This method enables robust and reliable speciation of bromine containing species in drinking water, with no salinity-related recovery issues. Thanks to the high sensitivity and completely metal free sample and mobile phase flow paths, the application complies to EPA 321.8 quality control requirements and provides MDLs well below the values necessary for accurate monitoring of water from various sources.
Skyrocketing costs of metal coating materials such as zinc have driven the need for improved process control. Anything other than the optimum coating thickness is unacceptable either from a quality control or cost control standpoint. The time has come for a fast, nondestructive, and accurate method of measuring coating thickness and coating weight, and analyzing plating bath solution. Handheld x-ray fluorescence (XRF) offers general metal finishers and others the advantage of at line testing, eliminating the need to cut samples and spend valuable time taking the sample to a benchtop analyzer to wait for results.
A Vanquish Flex Quaternary UHPLC system was applied for the SEC analysis. This is a low dispersion, inert UHPLC, which can be used successfully for this type of application. For this analysis, pre-column dispersion was intentionally introduced to show the effects of dispersion in front of the column at different flow rates.
Bischoff公司的独特键合技术使ProntoSIL C18 AQ 特别适用于有机溶剂含量低于10%的水系流动相环境。采用传统键合技术生产的固定相在这种水系条件下,刷状C18链会发生塌陷,导致峰形变差;而ProntoSIL C18AQ 在这种流动相中可以维持良好的峰形,这一优点大大提高了其选择性,这在分析极性物质时得到了充分体现。与ProntoSIL C18 AQ相似,ProntoSIL C18 AQ Plus 也适用于有机溶剂含量低于10%时的水系流动相。不同的是,ProntoSIL C18AQ Plus在低pH的酸性条件下(pH=1)显示了更强的稳定性。即使在以纯水为流动相的体系中,也能获得良好的峰形。
End functionalized poly(propylene oxide)s with n-alkyl endgroups are synthesized by anionic ring opening polymerization of propylene oxide (PO) in bulk employing controlled microwave heating in sealed vessels. Different alcohols rangingfrom n-butanol to n-octadecanol are used as initiator and 2–10 propylene oxide units are added on average. A continuous decrease of internal pressure during the sealed vessel experiment reflects the consumption of PO monomer and the completion of the reaction is confirmed by a drop of the internal pressure to zero. The products are characterized by size exclusion chromatography (SEC), liquid chromatography at critical conditions (LCCC) and liquid adsorption chromatography (LAC). SEC with coupled density and refractive index (RI) detection provides information on the chemical compositionalong the molar mass distribution. LCCC allows a separation of the individual polymer homologous series according to their end groups. In LAC, the alkyl terminated chains elute later than the non-functional chains and can be separated to the baseline according to the number of repeat units.
Non-destructive optical monitoring of chemical composition can beaccomplished using Raman Spectroscopy. Raman spectra can be utilisedto distinguish differences in chemical bond structures. This is particularly useful in applications where reactions could progress towards either a desired product or an undesired by-product. The Raman spectrum indicates when local conditions exist which favour one reaction path over another. This qualitative measurement can be developed into a tool to monitor process conditions.
We report here the results of further study of cryopreserved neonatal rat ventricular cardiac myocytes to determine their responsiveness in culture to challenge with positive chronotropic compounds, as well as determination of whethermyocardial hypertrophy can be evaluated using cultures prepared with cryopreserved cardiac myocytes.
Through the combination of the ICS-5000 ion chromatography system with the iCAP Qc ICP-MS, a sensitive, robust method for the speciation analysis of trace levels of Cr (III) and Cr (VI) in natural waters has been developed. The method developed enables fast and reliable speciation analysis of both Cr (III) and Cr (VI) species in water samples without prior incubation steps and with high purity nitric acid as mobile phase. The short, but highly ef?cient Dionex AG-7 column, provides complete separation of both species in under 150 s, enabling high sample throughput for the routine analysis of water samples.
In this study, a workflow is presented that combines fast chromatography, using two sizes of monolithic columns,and high resolution Orbitrap mass spectrometry of intact,as well as reduced, rituximab, sequence verification by AIF,and multiplexed HCD top-down fragmentation,supplemented by a bottom-up approach.
The biopharmaceutical industry continues to increase its focus on the development of biotherapeutic monoclonal antibody (mAbs) drugs. Early in the development of recombinant mAbs, a large number of harvest cell culture (HCC) samples must be screened for IgG titer,aggregations, and charge variants.
Electron imaging and Raman spectroscopy are established techniques for viewing and analysing carbon nanotubes. Performing these two techniques usually requires the sample being transferred between a scanning electron microscope(SEM) and a Raman spectrometer. This application note illustrates the advantages of Renishaw^^s structural and chemical analyser(SCA) for imultaneous secondary electron imaging and Raman spectroscopy of single-wall carbon anotubes(SWNTs).
Reported herein is the total synthesis of zincophorin methyl ester, a polyketide ionophore. Of particular interest is the use of sterically hindered nucleophiles to surmount the unfavorable stereochemical outcome, leading to acetate aldol adducts, in nucleophilic addition to the aldehyde derived from propionates. The approach is based on the addition of an enoxysilane (bearing a removablephenylselenide moiety) to generate selectively FelkineAnh adducts in a BF3,OEt2-mediated Mukaiyama aldol reaction. Subsequent reduction of the selenide group led to the corresponding syn-aldol acetate motif, and this approach was applied to induce selectively the C12eC13 relationship of zincophorin.
In order to solve the problem of baseline drift caused by spectral lines of oil spectrometer an adaptive niteratively reweighted penalized least squares method is proposed to correct the baseline.The oil spectrometer of Kunshan Soohow Instrument Technology Co.Ltd. was used to measure the contents of various elements in the standard oil with four concentrations of 0ppm,10ppm, 30ppm and 50ppm. The spectral line data collected by the first CCD was processed, and a good baseline correction efect was obtained.