Ultra performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UPLC-MS/MS) has been applied for the accurate and rapid analysis of nine trace level priority pesticides in water. The UPLC technology, based on the use of columns packed with 1.7 microm porous particles combined with higher pressures than those conventionally applied in HPLC, enabled to improve in peak resolution, sensitivity and speed of analysis. UPLC chromatograms showed very sharp peaks with less than 2 s wide at the base, except for alachlor. This enhanced efficiency resulted in an increased separation speed of the whole UPLC-MS/MS procedure that required less than 5 min. Limits of detection, determined for 300 ml water samples after SPE preconcentration were in the range between 0.1 and 20 ng/L. The presence of matrix effects or ion suppression was checked by the obtaining of calibration curves in both pure solvent and matrix matched standards. Other performance characteristics of the method, such as linearity and precision were also satisfactory. Finally, the method was successfully applied to the analysis of two water samples from an inter-laboratory exercise.
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http://dx.doi.org/10.1016/j.chroma.2006.01.024 | DOI Listing |
Sci Rep
January 2025
Multidisciplinary Center for Infrastructure Engineering, Shenyang University of Technology, Shenyang, 110870, China.
The current research introduces a model-free ultra-local model (MFULM) controller that utilizes the multi-agent on-policy reinforcement learning (MAOPRL) technique for remotely regulating blood pressure through precise drug dosing in a closed-loop system. Within the closed-loop system, there exists a MFULM controller, an observer, and an intelligent MAOPRL algorithm. Initially, a flexible MFULM controller is created to make adjustments to blood pressure and medication dosages.
View Article and Find Full Text PDFNat Commun
January 2025
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China.
Thin-film composite polyamide (TFC PA) membranes hold promise for energy-efficient liquid separation, but achieving high permeance and precise separation membrane via a facile approach that is compatible with present manufacturing line remains a great challenge. Herein, we demonstrate the use of lignin alkali (LA) derived from waste of paper pulp as an aqueous phase additive to regulate interfacial polymerization (IP) process for achieving high performance nanofiltration (NF) membrane. Various characterizations and molecular dynamics simulations revealed that LA can promote the diffusion and partition of aqueous phase monomer piperazine (PIP) molecules into organic phase and their uniform dispersion on substrate, accelerating the IP reaction and promoting greater interfacial instabilities, thus endowing formation of TFC NF membrane with an ultrathin, highly cross-linked, and crumpled PA layer.
View Article and Find Full Text PDFNat Commun
January 2025
School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA.
Energy efficiency in computation is ultimately limited by noise, with quantum limits setting the fundamental noise floor. Analog physical neural networks hold promise for improved energy efficiency compared to digital electronic neural networks. However, they are typically operated in a relatively high-power regime so that the signal-to-noise ratio (SNR) is large (>10), and the noise can be treated as a perturbation.
View Article and Find Full Text PDFTalanta
December 2024
The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, 523700, China. Electronic address:
This research presents a systematic review of the application of metal-organic frameworks (MOFs) to detect volatile organic compounds (VOCs). VOCs, compounds with high vapor pressure at ambient temperature and normal pressure, are widely present in a variety of industrial and living environments. VOCs are not only hazardous to the environment but also have a severe impact on human health.
View Article and Find Full Text PDFFood Chem
December 2024
College of Food Science and Technology, Hebei Agricultural University, Baoding 071001, China.
Fusarium sambucinum causes dry rot disease and postharvest storage losses in potatoes. Understanding the defense mechanisms of potato plants may lead to the development of rational disease control approaches. In the present study, "Kexin one" potato variety was infected with F.
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