118 results on '"Chan, W.-T."'
Search Results
102. A knowledge-based framework for the diagnosis of sludge bulking in the activated sludge process
- Author
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Koe, L. C. C. and Chan, W. T.
- Subjects
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SEWAGE disposal plants , *SEWAGE sludge , *SLUDGE bulking - Published
- 1991
103. ChemInform Abstract: Ring-Opening Reactions of Dioxetene, Oxetene, Dithiete, and Thiete.
- Author
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YU, H., CHAN, W.-T., and GODDARD, J. D.
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- 1991
- Full Text
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104. Computer-aided catchment-calibration model
- Author
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Liong, S.-Y., Ibrahim, Y., Chan, W. T., and Law, C. L.
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- 1993
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105. Neural Network: An Alternative to Pile Driving Formulas
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Chan, W. T., Chow, Y. K., and Liu, L. F.
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- 1995
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106. Parental attitudes on expanded newborn screening in Hong Kong.
- Author
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Mak, C. M., Lam, C. W., Law, C. Y., Siu, W. K., Kwong, L. L. T., Chan, K. L., Chan, W. T., Chow, KM., Lee, K. W., Chan, W. P., and Chan, A. Y. W.
- Subjects
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NEWBORN screening , *MEDICAL screening , *PARENT attitudes , *GENETIC disorders , *METABOLISM , *HOSPITALS - Abstract
Objectives: Classical inborn errors of metabolism (IEM) affect about 1 in 4000 in Hong Kong. Despite the widespread implementation of expanded newborn screening in most countries, Hong Kong only screen for three conditions and the awareness of public has not been evaluated. This is the first study to examine the parental knowledge and attitudes towards expanded newborn screening in Hong Kong. Methods: A cross-sectional survey was conducted in the Princess Margaret Hospital. Parents with babies bom from 1st July to 31st October 2010 were randomly recruited. Fifteen questions relating to the knowledge of newborn screening and biochemical genetic disorders, preferences about the features of newborn screening, the economic values, and attitudes toward false positive results were asked. Results: In total, 172 subjects were interviewed by phone (overall response rate 97.2%). There were 87.8% parents who had never heard of expanded newborn screening; 99.4% demanded more parental education; 83.5% thought the programme should be implemented immediately; 97.7% supported population screening, even though the diseases are incurable; 93.9% accepted the possibility of false positive and false negative results; 70.4% preferred a voluntary basis; 83.2% believed that the programme should be fully government funded as basic primary care; 98.8% agreed that Hong Kong should follow mainland China's policy on expanded newborn screening; 98.2% required pre-test counseling; and 96.4% required an explicit parental consent before blood sampling. Conclusions: The response from parents overwhelmingly favoured having expanded newborn screening in Hong Kong. Parental tolerance was high. Parents valued the parental autonomy with informed consent and pre-test counseling the most. The success of any screening programme requires the public participation and this study is the first to prove the parental call for an expanded newborn screening in Hong Kong. [ABSTRACT FROM AUTHOR]
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- 2012
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107. Catatonia and osmotic demyelination syndrome in a patient with schizophrenia: a case report.
- Author
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Choi HY, Chiu BMM, Wong YK, and Chan WT
- Abstract
Competing Interests: All authors have disclosed no conflicts of interest.
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- 2024
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108. Visual supplementation is an effective tool in cataract surgery counselling by eye-care practitioners.
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Chan WT, Wu D, Lim XH, Du R, Jeyabal P, Ng L, Nabhan TI, Lim DK, Stapleton F, and Lim HL
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- Humans, Female, Male, Aged, Middle Aged, Informed Consent psychology, Preoperative Care methods, Preoperative Care standards, Aged, 80 and over, Surveys and Questionnaires, Audiovisual Aids, Patient Satisfaction, Referral and Consultation, Cataract Extraction methods, Cataract Extraction psychology, Counseling methods, Patient Education as Topic methods
- Abstract
Background: Informed consent constitutes an important aspect of eye care. However, patients often experience difficulties understanding and retaining information presented to them during consultations. This study investigates the efficacy of pictorial aids in supplementing preoperative counselling of patients undergoing cataract surgery., Methods: Patients attending routine pre-cataract surgery counselling were randomized to receive either a standard verbal consultation (control) or a verbal consultation with a digitalized pictorial aid illustrating key surgical steps (intervention). Patients were assessed after the consultation on their knowledge, satisfaction, anxiety and preparedness using an anonymous questionnaire., Results: Seventy-six patients were recruited and randomized into the control and intervention groups. The intervention group attained better Knowledge Scores (control: 5 [2-6] vs. intervention: 6 [6]), and more patients "strongly agreed" that they were more prepared (control: 78.9% vs. intervention: 97.4%, P=0.028). A higher proportion of patients in the control group either "disagreed" or "neither disagree nor agreed (neutral)" that they were less worried (control: 15.8% vs. intervention: 0.0%, Fisher's Exact Test P=0.025). Although the consultation duration was shorter in the intervention group (21±4mins vs. 27±6mins, P<0.001), the use of digital pictorial aids during consultation resulted in more effective counselling with increased patient knowledge, easier decision-making process and reduced patient anxiety., Conclusion: Pictorial aids add to the repository of tools available to eye-care practitioners and are low-cost, easy to implement, and can effectively augment existing preoperative counselling processes to ensure accurate and effective preoperative counselling of patients., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)
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- 2024
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109. Salinity-dependent toxicities of zinc oxide nanoparticles to the marine diatom Thalassiosira pseudonana.
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Yung MM, Wong SW, Kwok KW, Liu FZ, Leung YH, Chan WT, Li XY, Djurišić AB, and Leung KM
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- Diatoms drug effects, Nanoparticles toxicity, Salinity, Water Pollutants, Chemical toxicity, Zinc Oxide toxicity
- Abstract
This study comprehensively investigated the influences of salinity, exposure concentration and time on the aggregate size, surface charge and dissolution of zinc oxide nanoparticles (ZnO-NPs; 20nm) in seawater, and examined the interacting effect of salinity and waterborne exposure of ZnO-NPs on the marine diatom Thalassiosira pseudonana for 96h. We found that aggregate sizes of ZnO-NPs significantly increased with increasing salinity, but generally decreased with increasing exposure concentration. Ion release decreased with increasing salinity, whereas the surface charge of the particles was not affected by salinity. The increased aggregate size and decreased ion release with increasing salinity, and consequently lower concentration of bioavailable zinc ions, resulted in decreased toxicity of ZnO-NPs at higher salinity in general in terms of growth inhibition (IC50) and chlorophyll fluorescence (EC50 - ФPo and EC50 - Ф2). However, IC50s and EC50s of ZnO-NPs were smaller than those of Zn(2+) (from ZnO-NPs ultrafiltrate and ZnCl2), indicating that dissolved Zn(2+) can only partially explain the toxicity of ZnO-NPs. SEM images showed that ZnO-NPs attached on the diatom frustule surface, suggesting that the interaction between the nanoparticles and the cell surface may acerbate the toxicity of ZnO-NPs. Our results linked the physicochemical characteristics of ZnO-NPs in seawater with their toxicities to the marine diatom and highlighted the importance of salinity as an influential environmental factor governing the aggregation, dissolution and the toxicity of ZnO-NPs., (Copyright © 2015 Elsevier B.V. All rights reserved.)
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- 2015
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110. Mad honey poisoning mimicking acute myocardial infarction.
- Author
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Chen SP, Lam YH, Ng VC, Lau FL, Sze YC, Chan WT, and Mak TW
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- Abdominal Pain etiology, Atropine therapeutic use, Chest Pain etiology, Electrocardiography, Humans, Male, Middle Aged, Diterpenes urine, Honey poisoning, Myocardial Infarction diagnosis
- Abstract
We report a case of acute poisoning in a 48-year-old man who presented with chest pain, abdominal pain, dizziness, sweatiness, blurred vision, and severe hypotension after ingestion of honey. His electrocardiogram showed sinus bradycardia and transient ST elevation. He made a good recovery after treatment with atropine and close monitoring. Grayanotoxin was detected in his urine and the honey he ingested, which confirmed a diagnosis of mad honey poisoning. This is a condition prevalent in the Black Sea region around Turkey but rarely seen locally. Although mad honey poisoning is life-threatening, early use of atropine is life-saving. Such poisoning may present with ST elevation in the electrocardiogram and symptoms mimicking acute myocardial infarction. It is therefore essential for clinicians to recognise this unusual form of poisoning and avoid the disastrous use of thrombolytic therapy.
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- 2013
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111. Outbreak of hypoglycaemia: sexual enhancement products containing oral hypoglycaemic agent.
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Poon WT, Lam YH, Lee HH, Ching CK, Chan WT, Chan SS, Lai CK, Tse ML, Chan AY, and Mak TW
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- Administration, Oral, Adult, Aged, Aged, 80 and over, Drug Combinations, Glyburide administration & dosage, Hong Kong, Humans, Hypoglycemia chemically induced, Hypoglycemic Agents administration & dosage, Male, Middle Aged, Piperazines administration & dosage, Purines administration & dosage, Purines adverse effects, Retrospective Studies, Sildenafil Citrate, Sulfones administration & dosage, Vasodilator Agents administration & dosage, Disease Outbreaks statistics & numerical data, Glyburide adverse effects, Hypoglycemia epidemiology, Hypoglycemic Agents adverse effects, Piperazines adverse effects, Sexual Behavior, Sulfones adverse effects, Vasodilator Agents adverse effects
- Abstract
Objectives: To describe a cluster of Hong Kong subjects with hypoglycaemia, after they had taken various non-prescription sildenafil products containing glibenclamide., Design: Retrospective study., Setting: A tertiary referral centre for clinical toxicology analysis in Hong Kong., Patients: All men referred to the laboratory for investigation of suspected drug-induced hypoglycaemia from December 2007 to September 2008., Main Outcome Measures: The characteristics of these patients, including their clinical presentations, outcomes, drug history, urine toxicology analysis results, and in some instances, analysis results of unused products., Results: A total of 144 male patients were referred for suspected drug-induced hypoglycaemia. Sildenafil and glibenclamide, or their metabolites, were detected in the urine specimens of 68 (47%) patients, none of whom had been prescribed either drug by a registered medical practitioner. Among these subjects, 24 (35%) denied any use of sexual enhancement products despite repeated questioning. Eight patients had repeated exposure resulting in re-admission. The sources of these sexual enhancement products included pharmacies in Mainland China, friends, local pharmacies, peddlers, or were unknown. Three patients died, one remains in a vegetative state and one suffered cognitive impairment; the remaining 63 recovered fully. Twenty-five unused sexual enhancement products of seven different kinds were recovered for analysis. The median (range) of sildenafil and glibenclamide per unit dose was 64 (0.05-198) mg and 70 (0-158) mg, respectively., Conclusion: These illegal products pose a severe and continued threat to society and therefore deserve widespread vigilance, so that such products can be eradicated at their source.
- Published
- 2009
112. Pediatric Salmonella enterocolitis in a teaching hospital in Taitung: A four-year analysis.
- Author
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Chi H, Sun W, Chan WT, Lee HC, and Fang SB
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- Bacteremia diagnosis, Bacteremia epidemiology, Bacteremia microbiology, Child, Child, Preschool, Enterocolitis diagnosis, Female, Hospitals, Teaching, Hospitals, Urban, Humans, Incidence, Infant, Infant, Newborn, Male, Risk Factors, Salmonella Infections microbiology, Seasons, Serotyping, Taiwan epidemiology, Enterocolitis epidemiology, Enterocolitis microbiology, Salmonella Infections diagnosis, Salmonella Infections epidemiology
- Abstract
In order to understand the childhood Salmonella enterocolitis in Taitung, we retrospectively collected the patients with the diagnosis of acute enterocolitis who were admitted to the pediatric wards of Taitung branch of Mackay Memorial Hospital from January 1, 1995 to December 31, 1998. Salmonella enterocolitis accounted for 16.8% of the total cases of acute enterocolitis. The mean age of the patients was 14.6 +/- 14.1 months old. Seventy-nine patients were male and 78 patients were female. Eighty-two patients lived in the urban area and 75 patients lived in the suburbs. The mean duration from onset of illness to admission was 2.6 +/- 1.9 days. The mean duration of hospitalization was 6.6 +/- 4.8 days. The peak incidence was in August and September. The most common clinical manifestations were fever (74.5%) and blood stool (46.5%). In 157 patients, Salmonella serogroup B was isolated from stool in 115 patients. The rate of bacteremia was 4.5%. Serogroup D accounted for 28.6% of the bacteremia. Two patients developed meningitis and one patient had osteomyelitis. Of 88 patients examined for rotavirus, 12 had positive results. There was neither bowel perforation nor mortality recorded in our study.
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- 2001
113. Metal speciation using capillary electrophoresis--inductively coupled plasma atomic emission spectrometry and polytetrafluoroethylene capillaries.
- Author
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Deng B and Chan WT
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- Electrophoresis, Capillary instrumentation, Metallothionein isolation & purification, Nebulizers and Vaporizers, Polytetrafluoroethylene, Electrophoresis, Capillary methods, Metals isolation & purification, Spectrum Analysis methods
- Abstract
A capillary electrophoresis--inductively coupled plasma atomic-emission spectrometry (CE-ICP-AES) system using a polytetrafluoroethylene (PTFE) capillary has been developed. The CE-ICP interface was a modified concentric nebulizer. The PTFE capillary (50 microm internal diameter) was used as the central capillary of the nebulizer. Using the PTFE capillaries, the solution flow rate induced by the carrier gas flow was smaller than that of glass capillary. Solution flow was mainly induced by the CE electric field. Baseline separation of Ba2+/Mg2+ ion pair using simple buffer solution of 0.014 M sodium acetate was reported. Separation and correlation of metal species in metallothioneins (MT-1 and MT-2 in MT) of rabbit liver using the CE-ICP system were also discussed.
- Published
- 2001
- Full Text
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114. Persistence of Mycobacterium tuberculosis in macrophages and mice requires the glyoxylate shunt enzyme isocitrate lyase.
- Author
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McKinney JD, Höner zu Bentrup K, Muñoz-Elías EJ, Miczak A, Chen B, Chan WT, Swenson D, Sacchettini JC, Jacobs WR Jr, and Russell DG
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- Animals, Fatty Acids metabolism, Isocitrate Lyase genetics, Lung microbiology, Macrophage Activation, Macrophages immunology, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Knockout, Mutagenesis, Mycobacterium tuberculosis enzymology, Mycobacterium tuberculosis immunology, Mycobacterium tuberculosis pathogenicity, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Tuberculosis enzymology, Tuberculosis immunology, Virulence genetics, Bacterial Proteins, Isocitrate Lyase physiology, Macrophages microbiology, Mycobacterium tuberculosis physiology, Tuberculosis microbiology
- Abstract
Mycobacterium tuberculosis claims more human lives each year than any other bacterial pathogen. Infection is maintained in spite of acquired immunity and resists eradication by antimicrobials. Despite an urgent need for new therapies targeting persistent bacteria, our knowledge of bacterial metabolism throughout the course of infection remains rudimentary. Here we report that persistence of M. tuberculosis in mice is facilitated by isocitrate lyase (ICL), an enzyme essential for the metabolism of fatty acids. Disruption of the icl gene attenuated bacterial persistence and virulence in immune-competent mice without affecting bacterial growth during the acute phase of infection. A link between the requirement for ICL and the immune status of the host was established by the restored virulence of delta icl bacteria in interferon-gamma knockout mice. This link was apparent at the level of the infected macrophage: Activation of infected macrophages increased expression of ICL, and the delta icl mutant was markedly attenuated for survival in activated but not resting macrophages. These data suggest that the metabolism of M. tuberculosis in vivo is profoundly influenced by the host response to infection, an observation with important implications for the treatment of chronic tuberculosis.
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- 2000
- Full Text
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115. Characterization of a zebrafish (Danio rerio) desmin cDNA: an early molecular marker of myogenesis.
- Author
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Loh SH, Chan WT, Gong Z, Lim TM, and Chua KL
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- Amino Acid Sequence, Animals, Base Sequence, Blotting, Northern, Cloning, Molecular, DNA Primers chemistry, Desmin metabolism, Embryo, Nonmammalian cytology, Gene Expression Regulation, Developmental, Genetic Markers, Heart physiology, In Situ Hybridization, Molecular Sequence Data, MyoD Protein metabolism, Myogenin metabolism, Reverse Transcriptase Polymerase Chain Reaction, Sequence Homology, Amino Acid, Somites cytology, Zebrafish embryology, DNA, Complementary genetics, Desmin genetics, Zebrafish genetics
- Abstract
Desmin is a muscle-specific protein and a constitutive subunit of the intermediate filaments (IF) in skeletal, cardiac and smooth muscles. It is an early marker of skeletal muscle myogenesis. We have characterized a clone of desmin cDNA from an embryonic zebrafish (Danio rerio) cDNA library. The full-length cDNA comprised 1798 nucleotides, encoding a protein of 473 amino acids. The predicted amino acid sequence of the zebrafish desmin shares a high degree of similarity to other vertebrate desmins, but also contains a sequence at the carboxyl terminal of the tail domain that is unique to the zebrafish. It carries many features which are distinctive of IF subunit proteins. These include the T/SSYRRXF/Y motif in the head domain, and the intermediate filament signature consensus, [I/V]-X-[T/A/C/I]-Y-[R/K/H]-X-[L/M]-L-[D/E], located in the carboxyl terminus of the central helical rod. Unlike other 3' UTR sequences, the 3' UTR of the zebrafish cDNA sequence has two CAYUG elements flanking a single polyadenylation site. The temporal and spatial expression patterns of desmin mRNA during early zebrafish development were studied. The onset of desmin expression occurred at the 1-3 somite stage (11 hpf). It increased throughout somitogenesis, with maximum expression at the Prim-6 stage (25 hpf), and decreasing expression towards the protruding-mouth stage (72 hpf). Desmin mRNA was initially localised exclusively to the somites, but was subsequently also detected in other musculature in the developing heart and fins. The onset of expression and the spatial localization of desmin mRNA in the zebrafish coincides with that reported for MyoD and myogenin.
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- 2000
- Full Text
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116. Interface for capillary electrophoresis coupled with inductively coupled plasma atomic emission spectrometry.
- Author
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Chan YY and Chan WT
- Subjects
- Electrodes, Electrolysis, Electrophoresis, Capillary instrumentation, Nebulizers and Vaporizers, Spectrum Analysis, Time Factors, Chromium analysis, Electrophoresis, Capillary methods
- Abstract
A modified concentric nebulizer was used as the interface to couple capillary electrophoresis (CE) to inductively coupled plasma atomic emission spectrometry (ICP-AES). The CE capillary replaces the central tube of the concentric nebulizer. The tip of the nebulizer tapers slowly to allow uncertainty in the position of the capillary. A platinum wire was inserted into the CE capillary to provide electrical connection to the CE power supply. pH changes inside the capillary due to electrolysis of the background buffer electrolyte was small and has minimal effects on the CE separation. The peak broadening effects due to the nebulizing gas flow, however, were significant. Resolution decreases quickly when the flow-rate of the carrier gas increases. Sample stacking technique was used to improve the resolution of species of opposite charge, e.g., Cr(VI) vs. Cr(III) ions. Detection limit of Cr based on peak area is approximately 10 ppb for the CE-ICP-AES system.
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- 1999
- Full Text
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117. Locus of control and occupational stress in Chinese professionals.
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Hamid PN and Chan WT
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- Adult, Factor Analysis, Statistical, Female, Hong Kong, Humans, Male, Internal-External Control, Occupational Health, Stress, Psychological psychology
- Abstract
The relationship between scores on locus of control, occupational stress, and stress symptoms was examined in 189 Hong Kong Chinese professionals. Scores on locus of control were associated with occupational stress and psychological stress symptoms but were unrelated to reporting of physical symptoms. While both sexes reported similar occupational stress, women scored as more External and reported more of both types of symptoms. The implications of the results were discussed.
- Published
- 1998
- Full Text
- View/download PDF
118. Sample preconcentration using ion-exchange polymer film for laser ablation sampling inductively coupled plasma atomic emission spectrometry.
- Author
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Chan WT and Yip HH
- Abstract
An efficient sample pretreatment/introduction technique for the inductively coupled plasma atomic emission spectrometry (ICP-AES) using ion exchange for analyte preconcentration and matrix separation and laser ablation sampling for sample introduction has been developed. Ammonium pyrrolidine dithiocarbamate (APDC)-polystyrene films are coated on glass plates for analyte preconcentration. Repetitive laser ablation sampling of the polymer film removes the ion-exchanged metal ions from the polymer film as fine particles for sample introduction into the ICP. After immersing the sample probe in a sample solution for 5 min, the ICP emission intensity for laser ablation of the polymer film is a few times larger than that after solution nebulization. The sample probe removes only a small fraction of the sample solution and, therefore, in principle, does not disturb the original solution significantly. Single-pulse laser ablation of the polymer film shows that the ion-exchanged metal ion concentration in the film reduces exponentially with the depth of the polymer film. Ion exchange to the polymer film is probably limited by the rate of metal ion diffusion into the film. Calibration curves for Cu, Hg, Pb, and Zn show linear dynamic range of ∼1-2 orders of magnitude. The linear dynamic range for Cu increases to >3 orders of magnitude when using Pb as an internal standard. RSD of the ICP emission intensity is ∼8%.
- Published
- 1997
- Full Text
- View/download PDF
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