Publications by authors named "Judy Lum"

Using current water treatment systems, significant amounts of microplastics (MPs) are passing through and being released into the aquatic environment. However, we do not clearly know what effects disinfection processes have had on these particles. In this study, we applied inductively coupled plasma-mass spectrometry (ICP-MS) operating in time-resolved analysis (TRA) mode for quantifying changes in the chlorine (Cl) content of MPs under a variety of water treatment scenarios.

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The aim of this pilot study was to predict the risk of gestational diabetes mellitus (GDM) by the elemental content in fingernails and urine with machine learning analysis. Sixty seven pregnant women (34 control and 33 GDM patient) were included. Fingernails and urine were collected in the first and second trimesters, respectively.

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Single particle-inductively coupled plasma-mass spectrometry (SP-ICP-MS) was used in the analysis of single particles/cells. Although quadrupole mass analyzers are widely used, the long settling time restricts measurement to single elements in individual particles. Recently, dual-elemental analysis has successfully been developed with the assistance of oxygen gas in the collision cell.

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Cerium dioxide nanoparticles (CeO NPs) are widely used in various fields, leading to concern about their effect on human health. When conducting in vivo investigations of CeO NPs, the challenge is to fractionate ionic Ce and CeO NPs and to characterize CeO NPs without changing their properties/state. To meet this challenge, we developed an integrated inductively coupled plasma-mass spectrometry (ICP-MS)-based analytical approach in which ultrafiltration is used to fractionate ionic and nanoparticulate Ce species while CeO NPs are characterized by single particle-ICP-MS (sp-ICP-MS).

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Single-particle inductively coupled plasma-mass spectrometry (SP-ICP-MS) is used for elemental analysis of single particles and biological cells. Time-of-flight (TOF) mass analyzers are widely used for multiple element analysis of individual particles. Owing to the sequential nature of the mass analyzer, quadrupole-based ICP-MS generally gives poor analytical performance when more than one element are being monitored.

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Article Synopsis
  • Humans are exposed to various environmental pollutants, and abnormal levels of essential elements in the body can be linked to different diseases.
  • Although blood is commonly used for biomonitoring, it only indicates short-term exposure and involves invasive sampling, leading researchers to explore non-invasive alternatives like hair, nails, and urine.
  • The review discusses analytical methods for non-invasive samples, including sample collection and preparation, while addressing the need for better correlations between these samples and blood for effective human biomonitoring.
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Information on the risk of exposure to cerium oxide (CeO) nanoparticles (NPs) is limited. To assess risk, we must know where and how such NPs are distributed to the body after exposure, both short- and long-term. In this work, an integrated approach of quantitative LA-ICP-MS bioimaging and fractionation was employed to study the translocation and transformation of CeO and Ce in mouse spleen and liver.

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In this study, a method of simultaneous dual mass detection for single cell analysis by quadrupole-based ICP-MS (ICP-QMS) is proposed. The method shows potential for use in quantitative investigations of nanoparticle association and elemental composition of cells. Dual mass detection had been attempted in the analysis of two-element core-shell nanoparticles and in isotope dilution analysis.

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Chemical analysis of Chinese black ink on xuan paper is useful for the authentication of Asian artwork. The analysis has to be nondestructive and has to accommodate artworks of all sizes. We apply three analytical techniques, ArF laser-induced plume fluorescence, Fourier transform infrared (FTIR) spectroscopy, and portable X-ray fluorescence (pXRF) to analyze five commercial Chinese black inks on two kinds of xuan paper.

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