ABSTRACTS
This page gives details of the abstract for PSA oral and posters presentations
UK
EUROPE
THE AMERICAS
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UK
BNASS 2008
Using Millennium Excalibur for the Speciation of Arsenic and Selenium Metabolites in Human Urine
Sampling – Still the Achilles Heel for Accurate Mercury Measurements in Petrochemical Samples
EUROPE
2nd INTERNATIONAL CONGRESS - ARSENIC IN THE ENVIRONMENT
4th INTERNATIONAL CONFERENCE ON TRACE ELEMENT SPECIATION IN BIOMEDICAL, NUTRITIONAL AND ENVIRONMENTAL SCIENCES
APPLICATION OF MASS SPECTROMETRY TO SPECIATION ANALYSIS IN THE LIFE SCIENCES
TRACESPEC 2007
THE AMERICAS
PITTCON 2008
Using Millennium Excalibur for the Speciation of Arsenic and Selenium
Metabolites in Human Urine
Performing EPA Methods 245.7 and 1631 with PSA Millennium Merlin System
Field Experience of a Mercury Continuous Emission Monitoring System
EPA 17th Annual Conference
Development of Hg Calibration Systems for Hg CEM Applications
Air Quality VI: Mercury, Trace Elements...
REST OF WORLD
No conferences listed at present.
ABSTRACTS
BNASS 2008
25 Years Experience of Vapour Generation Techniques for quantifying Mercury Levels in a Range of Environmental Samples
Peter B Stockwell, Warren Corns and Jasmina Allen
P S Analytical began its life as a designer of vapour generation systems for the measurement of the hydride forming elements and mercury by atomic absorption spectrometry. In 1983 a semi-automated system was developed for commercial atomic absorption spectrometry. However, the full potential of the technique was not fully realised until 1987, when the technique was coupled to atomic fluorescence spectrometry and commercialised. Whilst other measurement techniques are now commonly used for the determination of arsenic, antimony, selenium and mercury, atomic fluorescence spectrometry offers significant advantages when reliable, precise measurements are required. The vapour generation AFS approach can also be coupled to chromatographic techniques to provide speciation profiles for these elements and ensure correct treatment in order to take preventative action on these environmental samples.
Using Millennium Excalibur for the Speciation of Arsenic and Selenium Metabolites in Human Urine
Bin Chen, Jasmina Allen, Warren T Corns and Peter B Stockwell
Urinary As and Se metabolites are used frequently in epidemiological and environmental health studies as a means of assessing exposure to As and Se from various sources. The concentrations of urinary As and Se methylation are often found low enough (~ ng/ml) which require sensitive analytical methods involving speciation, identification and quantification of each individual species. Using Millennium Excalibur system based on high performance liquid chromatography coupled with hydride generation atomic fluorescence spectroscopy (HPLC-HG-AFS), As metabolites such as arsenobetaine, arsenite, dimethylarsenic acid, monomethylarsonic acid and arsenate, and Se metabolites such as selenosugar, selenite, selenate, selenomethionine, selenoethionine have been separated using ion-pairing reverse phase HPLC within 10 and 15 minutes for As and Se, respectively. A mobile phase of pH 9 containing 20mM ammonium phosphate, 5mM TBAH and 4% ethanol was used for As speciation, and a mobile phase of pH 4 containing 30mM Ammonium Formate, 1% methanol, and 0.01mM DDAB. The eluent was further digested using an online post column UV digestion device at 200 °C, followed by the sensitive detection of HGAFS which was able to provide detection limits of 0.4-0.8 ng/ml for all the As and Se species.
Sampling – Still the Achilles Heel for Accurate Mercury Measurements in Petrochemical Samples
Matthew Dexter, Warren T Corns and Peter B Stockwell
As we increase our knowledge of measurement techniques in analytical science, little, if any, effort is being made on the Achilles Heel of analysis – the provision of a truly representative sample. Mercury is of considerable interest in the Petrochemical industry as it causes many failures of processing plants. Atomic fluorescence measurements, combined with well designed sampling strategies provide the Petrochemical industry with three mechanisms to (a) determine the levels of mercury present in the samples (b) the precise distribution of the mercury species and (c) the mechanisms to remove the mercury species and render the sample suitable for continuing use in the industry.
Atomic fluorescence spectrometry provides a viable measurement tool which coupled to tailored sampling systems for both online and offline applications serve the industry well. Experiences operating several systems which range from natural gas to liquefied natural gas condensates will be described. Many of these systems have been operating continuously since 1996.
2nd INTERNATIONAL CONGRESS - ARSENIC IN THE ENVIRONMENT
Determination of Arsenic Species using Liquid Chromatography coupled to Hydride Generation Atomic Fluorescence Spectrometry
Prof Peter Stockwell, Dr Warren Corns, Dr Bin Chen and Jasmina Allen
Arsenic and its compounds are known to cause several adverse health effects including cancers of the skin, bladder, kidney, and lung, and diseases of the blood vessels of the legs and feet. P S Analytical supplies dedicated analysis systems for both total and species determination. Speciation is important to monitor levels of individual Arsenic species as the toxicity of certain elements depends very heavily on their physico-chemical form. Urinary As metabolites are used frequently in epidemiological and environmental health studies as a means of assessing exposure to As from various sources. The concentrations of urinary As methylation are often found to be at low enough levels (~ ng/ml) to require sensitive analytical methods involving speciation, identification and quantification of each individual species. Using Millennium Excalibur system based on high performance liquid chromatography coupled with hydride generation atomic fluorescence spectroscopy (HPLC-HG-AFS), As metabolites such as arsenobetaine, arsenite, dimethylarsenic acid, monomethylarsonic acid and arsenate have been separated using ion-pairing reverse phase HPLC within 10 minutes. A mobile phase of pH 9 containing 20mM ammonium phosphate, 5mM TBAH and 4% ethanol was used for the separation of Arsenic species. The eluent was further digested using an online post column UV digestion device at 200°C, followed by the sensitive detection of HGAFS which was able to provide sub ppb detection limits.
4th INTERNATIONAL CONFERENCE ON TRACE ELEMENT SPECIATION IN BIOMEDICAL, NUTRITIONAL AND ENVIRONMENTAL SCIENCES
Method Development for Selenium Speciation in Selenium Nutritional Supplements and Urine using HPLC UV-HG-AFS
Bin Chen, Tessy A Momoh, Warren T Corns and Peter B Stockwell
A new technique for the speciation of selenocysteine, selenomethionine, selenite, selenate and selenosugar1 was developed using high performance ion-pair reverse phase chromatography coupled with atomic fluorescence spectrometry.
Selenium species were separated using a mobile phase of pH 4 containing 40mM ammonium formate, 0.01mM DDAB, 0.5% (v/v) methanol at 0.8ml min-1 on a Gemini C18 column (250 x 4.6mm, 5µm) and then digested by online ultra violet (UV) irradiation at elevated temperature. Hydride generation was used as sample introduction technique, and this was maximized for all species by the optimization of variable analytical parameter. The final optimized conditions for UV-HG-AFS were 50% (v/v) HCl + 5% (m/v) KBr as oxidant, 0.8% (m/v) NaBH4 in 1% (m/v) NaOH as reductant, 250ml min-1 argon flow rate and 150°C temperature. Selenium nutritional supplements and urine samples were analyzed, and the detection limit obtained was range 0.9ng ml-1 to 3ng ml-1. One of the most significant findings of this research was that selenomethionine was found to be metabolized to selenosugar1 and excreted in urine.
APPLICATION OF MASS SPECTROMETRY TO SPECIATION ANALYSIS IN THE LIFE SCIENCES
Method Development For Selenium Speciation in
Selenium Supplement Tablets
and Urine - Using HPLC UV-HG-AFS
Tessy Momoh, Dr Warren Corns and Jasmina Allen, P S Analytical
A new technique for the speciation of Selenocysteine, Selenomethionine, Selenite, Selenate and Selenosugar (1) was developed using high performance ion-pair reverse phase chromatography coupled with atomic fluorescence spectrometry.
Selenium species were separated on a phenomenexä Gemini C18 column and then digested by online ultraviolet (UV) irradiation at an elevated temperature which destroyed high molecular organo-seleniums. Hydride generation was used as a sample introduction technique to improve sensitivity for the atomic fluorescence detection.
The hydride generation was maximized for all selenium species by optimizing the argon flow rates and the NaBH4 concentration. The online oxidation and breakdown of seleno-proteins was obtained by the optimization of the heater temperature. The final optimized conditions for UV-HG-AFS were 50% HCl with 5% KBr as oxidant, 0.8% NaBH4 in 1% NaOH as reductant, 250ml min-1 Argon Flow rate and 150ºC temperature. Final Optimized conditions for HPLC were phenomenexä Gemini 250 x 4.6mm C18, 40mM ammonium formate buffer + 1x10-5 DDAB + 0.5% MeOH as Mobile phase at 0.8ml min-1 and pH4. The detection limit range was 0.9 to 3ng ml-1.
Selenious yeast supplement and urine samples were analyzed. One of the most significant findings of this research was that SeMet was found to be metabolized to Selenosugar and excreted in urine.
TraceSpec 2007
Speciation of Five Arsenic Metabolites in Urine Using High Performance Liquid Chromatography and Post Column UV Digestion Coupled with Hydride Generation Atomic Fluorescence Spectrometry (HPLC-UV-HGAFS)
Dr Bin Chen, Warren T Corns, Peter B Stockwell, P S Analytical
Zorimar
Rivera-Nunez, Environmental Health Science, School of Public Health, University of Michigan, Ann Arbor, MI, USA
Arsenic and its compounds are known to cause several adverse health effects. Urinary As metabolites were used recently in epidemiological and environmental health studies as a means of assessing exposure to arsenic from drinking water. The concentrations of urinary As methylation are often found low enough (~ ng/ml) which require sensitive analytical methods involving speciation, identification and quantification of each individual As species. Arsenobetaine (AsB), arsenite (AsIII), dimethylarsenic acid (DMAV), monomethylarsonic acid (MMAV) and arsenate (AsV) have been separated in one single chromatogram run using ion-pairing reverse phase HPLC within 10 minutes. A mobile phase of pH 9 containing 20mM ammonium phosphate, 5mM TBAH and 4% ethanol was used. The eluent was further digested using an online post column UV digestion device at 200°C, followed by the sensitive detection of HGAFS which was able to provide detection limits of 0.4-0.8 ng/ml for all the arsenic species. The developed method provided a sensitive, robust approach for the monitoring of arsenic methylations in human urine samples.
Determination of Mercury Species in Portuguese Salt Marshes using Capillary GC - Atomic Fluorsecence Spectrometry
Dr Warren Corns, Prof Peter Stockwell and Dr Derek Bryce, P S Analytical
M Válega and E Pereira, University of Aveiro, Portugal
M Pardal, University of Coimbra, Portugal
Salt marshes located near by industrialised areas can act as natural sinks for trace metals. Anthropogenic metals, associated with suspended particulate matter can be transported by tidal currents and trapped by vegetation with subsequent incorporation into sediments. Plant roots can interact with the surrounding sediment, exuding oxygen and organic compounds that influence the distribution and availability of trace metals; however, the amount of metals taken up by the plants is dependent of the metal availability in the sediment, and this is modified by the root activity. Oxygenation of upper estuarine sediments decreases rapidly with depth due to the consumption of oxygen in the oxidation process of the organic matter; however, salt marsh sediments receive an additional input of oxygen in the sub-surface layers through the well developed aerenchyma of salt marsh plants (halophytes) which transports oxygen from leaves to roots and consequently to the surrounding sediments. This supply of oxygen can alter significantly the redox status of sediments with strong repercussions on the biogeochemistry of nutrients and trace elements, namely mercury. The methylation of mercury in salt marsh sediments is poorly documented, although abundant micro-organisms and strong redox gradients between roots and surrounding sediments may favour that process. Because the sediment environment in salt marshes is exceedingly complicated it is pertinent to investigate the conversion of inorganic mercury into organomercury species. A fully automated GC coupled to atomic fluorescence spectrometer will be described for the determination of methylmercury in sediments and salt marsh plants.
Pittsburgh Conference 2008
Using Millennium Excalibur for the Speciation of Arsenic and Selenium
Metabolites in Human Urine
Bin Chen, Tessy A Momoh, Warren T Corns and Peter B Stockwell, P S Analytical,
Arsenic and its compounds are known to cause several adverse health effects. Selenium behaves a dual role in human body both as toxicant and essential trace element at different concentration and the difference of the concentrations are very small. Because urine is a major excretory route for both As and Se, urinary As and Se metabolites were used recently in epidemiological and environmental health studies as a means of assessing exposure to As and Se from various sources. The concentrations of urinary As and Se methylation are often found low enough (~ ng/ml) which require sensitive analytical methods involving speciation, identification and quantification of each individual species. Using Millennium Excalibur system based on high performance liquid chromatography coupled with hydride generation atomic fluorescence spectroscopy (HPLC-HG-AFS), As metabolites such as arsenobetaine, arsenite, dimethylarsenic acid, monomethylarsonic acid and arsenate, and Se metabolites such as selenosugar, selenite, selenate, selenomethionine, selenoethionine have been separated using ion-pairing reverse phase HPLC within 10 and 15 minutes for As and Se, respectively. A mobile phase of pH 9 containing 20mM ammonium phosphate, 5mM TBAH and 4% ethanol was used for As speciation, and a mobile phase of pH 4 containing 30mM Ammonium Formate, 1% methanol, and 0.01mM DDAB. The eluent was further digested using an online post column UV digestion device at 200 °C, followed by the sensitive detection of HGAFS which was able to provide detection limits of 0.4-0.8 ng/ml for all the As and Se species. The developed methods provided sensitive, robust approaches for the monitoring of As and Se methylations in human urine samples.
Determination of Total Gaseous Mercury in Ambient Air using Amalgamation
coupled to Atomic Fluorescence Spectrometry
Warren T Corns and Peter B Stockwell, P S Analytical
Richard Brown and Andrew S. Brown, Analytical Science Group, National Physical Laboratory, Teddington, UK
Measurements of mercury in ambient air are assuming greater importance, because of increasing health concerns and legislative requirements. The general public and the environment can be exposed to mercury originating from natural, domestic or industrial processes. Coal-burning power plants are the largest anthropogenic source of mercury emissions to the air. Burning hazardous wastes, the chlor-alkali industry, crematoria, breaking mercury products, and spilling mercury, as well as the improper treatment and disposal of products or wastes containing mercury, can also release it into the environment.
In this paper we will describe automated online instrumentation based on amalgamation with atomic fluorescence spectrometry. A known volume of ambient air at a controlled flow rate is passed over a gold impregnated silica trap. Total Gaseous is pre-concentrated on the gold substrate by amalgamation. After the collection period the Hg is thermally desorbed and subsequently delivered to the atomic fluorescence spectrometer specifically designed to detect Hg. The analytical performance of the system will be presented along with data from rural, coastal and urban industrial sites from several European countries.
Performing EPA Methods 245.7 and 1631 with PSA Millennium Merlin System
Bin Chen, Warren T Corns and Peter B Stockwell, P S Analytical
Mercury is naturally present in aquatic systems in very low concentrations. Due to the long range atmospheric transport and deposition of anthropogenic mercury, elevated concentrations of mercury are found even in remote freshwater system although no direct local contamination sources are present. It is long recognised that mercury is one of the most hazardous toxicant to human and the environment. To protect people and the environment from the mercury, governments and regulatory agencies are introducing ever more stringent guidelines. As a result, analysts are challenged to achieve the ever greater sensitivity. The USEPA approved Method 245.7 and Method 1631 for the determination of low level total mercury in water. Both methods are based on vapor generation atomic fluorescence spectrometry (CV-AFS). In this work, a comparison between performing these two EPA methods with PSA Millennium Merlin system is presented. The methodology, operation procedure, analytical sensitivity, and the quality control criteria are compared in detail.
Field Experience of a Mercury Continuous Emission Monitoring System
Matthew A Dexter, Warren T Corns, Peter B Stockwell.
The Clean Air Mercury Rule provides a regulatory regime for the control of mercury emissions from coal-fired utilities in the United States. The rule requires the installation of continuous emission monitoring systems at the majority of such utilities and provides a detailed regime of tests to validate data from the emissions monitoring system. Elemental and oxidised mercury calibration gases traceable to national standards are required for the validation tests.
The P S Analytical Continuous Emission Monitoring System has been used to monitor gas-phase mercury concentrations in coal-fired utility stack gas. The instrument consists of a sampling probe, heated sample transfer line, sample conditioning system, analyser and calibration modules.
The sampling probe extracts sample from the stack, separates the gaseous sample from fly ash, and delivers the diluted sample to the sample conditioner via the heated sample line. The sample is conditioned to convert all mercury in the sample to elemental mercury and is delivered to the analyser without the need for water injection. Mercury in the sample is determined by amalgamation coupled with atomic fluorescence in the Sir Galahad Analyser, providing a method detection limit of less than 0.01 µg-3.
A calibration gas generator and delivery manifold system is incorporated to deliver known-concentration calibration gases to the sampling system for system integrity validation tests.
The various components of the PSA Hg CEM will be described and results of recent field experience of the system and compliance with the regulatory tests will be presented.
EUEC 2008
PSA are attending this conference.
EPA 17th Annual Conference
Development of Hg Calibration Systems for Hg CEM Applications
No abstract available please contact PSA for further information.
Air Quality VI: Mercury, Trace Elements...
Development and Testing of an Oxidised Mercury Calibration Gas Source for CEMs and Instrumental Reference Methods
Dr Matthew A Dexter, Dr Isabelle Atheaux, Dr Warren T Corns and Professor PeterB Stockwell, P S Analytical
The Clean Air Mercury Rule has provided the legislation for the regulation and control of mercury emissions from coal fired utilities in the United States. The rule requires periodic testing with elemental mercury and mercury(II) chloride calibration gases to ensure the integrity of the CEMs. These calibration gases are also required by the current draft Instrumental Reference Method. It is therefore essential to develop suitable calibration sources which are traceable to national standards (NIST or other standards bodies) for use in CEM and IRM testing.
Since the introduction of its first mercury continuous emissions monitor P S Analytical has provided a calibration source, the Cavkit, which allows an automatically adjustable set concentration of mercury to be introduced at various stages in the sampling and measurement cycle. This has been successfully used to check calibration and to test the integrity of CEM systems. The system has been evaluated by NIST.
A mercury(II) chloride calibration gas source has been developed for use in CEM and IRM testing. The HgCl2 generator can be located at the analyser or the sample probe to minimise sample transport issues. Development of the HgCl2 calibration gas generator and early experiences of this in the field will be described.
Rest of the World
