Agilent Technologies

About: Agilent Technologies is a company organization based out in Santa Clara, California, United States. It is known for research contribution in the topics: Signal & Mass spectrometry. The organization has 7398 authors who have published 11518 publications receiving 262410 citations. The organization is also known as: Agilent Technologies, Inc..

A hybrid switching control strategy for nonlinear and underactuated mechanical systems

Abstract: This note presents a hybrid switching control strategy for nonlinear and underactuated mechanical systems. Sufficient conditions for constructing the hybrid switching control, stability proof, and experimental results for using the hybrid switching control are given.

Determination of ultratrace 129I in soil samples by Triple Quadrupole ICP-MS and its application to Fukushima soil samples

Abstract: A method was developed for the determination of 129I in soil samples using a Triple Quadrupole ICP-MS, with the objective of investigating radioiodine released by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. The determination of 129I by ICP-MS is capable of providing a high sample throughput compared to other methods. Nonetheless, the high background caused by 129Xe impurities in argon plasma gas and polyatomic ions such as 127IH2+ and 127ID+ has made it difficult to carry out determinations of this isotope by conventional ICP-MS instruments. In this study, oxygen was used as a reaction gas for reducing the background intensity of m/z 129, principally by 129Xe. The contribution of polyatomic ions such as 127IH2+ and 127ID+ could be effectively corrected for by assuming a production ratio of 5 × 10−9. The detection limit for 129I in solution was successfully improved. The measured 129I/127I ratios in NIST SRM 3231 Level II standard solution are consistent with the certified value of 0.981 × 10−8 within the analytical error, suggesting the reliability of the method to the measurement of 129I/127I. In order to confirm the applicability of this method to the measurement of 129I/127I ratios of Fukushima soils, samples were collected for analysis from 5–60 km away from the FDNPP. Prior to the ICP-MS measurement iodine fractions were separated from soil by pyrohydrolysis and were purified by solvent extraction. The 129I/127I ratios in the samples are consistent with values determined by accelerator mass spectrometry (AMS) within the analytical error. This method provides a powerful tool for the investigation of radioiodine contamination in Fukushima and elsewhere.

Chemometric Determination of the Botanical Origin for Chinese Honeys on the Basis of Mineral Elements Determined by ICP-MS

Abstract: In this work, the potential of mineral elements and chemometric methods as a tool to classify Chinese honeys according to their botanical origin was examined. Twelve mineral elements (Na23, Mg24, P31, K39, Ca43, Mn55, Fe56, Cu63, Zn66, Rb85, Sr88, and Ba137) of 163 Chinese honey samples, including linden, vitex, rape, and acacia, collected from Heilongjiang, Beijing, Hebei, and Shaanxi, China, in 2013 were determined by the ICP-MS method. Principal component analysis (PCA) reduced 10 variables to four principal components and could explain 93.06% of the total variance. Partial least-squares discriminant analysis (PLS-DA) and back-propagation artificial neural network (BP-ANN) were explored to construct a classification model. By PLS-DA, the total correct classification rates for model training and cross-validation were 90.9 and 88.4%, respectively. By BP-ANN, the total correct classification rates for model training and cross-validation were 100 and 92.6%, respectively. The performance of BP-ANN was bette...

Loop-based multiple heart-cutting two-dimensional liquid chromatography for target analysis in complex matrices.

Abstract: Loop-based multiple heart-cutting (MHC) two-dimensional liquid chromatography (2D-LC) is presented as a solution to quantify target components in complex matrices, such as additives in polymers, at very high chromatographic resolution. The determination of hexabromocyclododecane (HBCD) in polystyrene (PS) is described. One dimensional ((1)D) LC analysis with UV detection did not allow quantitation of the main isomers of HBCD due to peak overlap with polymer components. MHC 2D-LC analysis provided the separation power, accuracy, and repeatability needed for quantitative analysis of the additives of interest. Heart-cuts from peaks of the (1)D-chromatogram or entire regions of interest are sampled into loops, where they remain parked until their sequential reinjection onto the second dimension ((2)D) column. A column set consisting of phenyl ((1)D) and C18 ((2)D) stationary phases gave baseline separation in (2)D between HBCD and PS background. Linearity for spiked polymer samples was achieved over a range of 0.02-1.00 wt % HBCD relative to the amount of polymer. The limit of quantitation was estimated at 0.01 wt % HBCD in PS. A peak area RSD of 0.7% obtained for ten replicates of a real sample demonstrated excellent repeatability of the analysis. MHC 2D-LC is an elegant solution for quantitative analyses of difficult-to-separate samples when conventional (1)D separation fails.

Semiquantitative reverse transcription-polymerase chain reaction with the Agilent 2100 Bioanalyzer.

Abstract: We have applied a method to monitor mRNA expression in a semiquantitative fashion on the Agilent 2100 Bioanalyzer. The method was originally described in 1994 by Wong et al. and referred to as the "primer-dropping" method. This polymerase chain reaction (PCR) technique uses multiple sets of primer pairs in a coamplification reaction that amplifies the target of interest within a predetermined range specific for each target. Separation, detection and quantification of PCR products were accomplished using the Agilent 2100 Bioanalyzer in conjunction with the DNA 500 and the DNA 1000 Lab-Chip kits for the detection of DNA fragments with a maximum size of 500 and 1000 bp, respectively. Using primers specific for the inducible form of hsp72 and primers for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal standard we were able to rapidly monitor and quantify inducible hsp72-mRNA expression.