This document describes methods for monitoring inorganic ions in ambient air using ion chromatography. Key points:
- Ion chromatography is described as the preferred technique for simultaneously analyzing sulfate, nitrate, chloride, and fluoride in ambient air samples. It allows for rapid sequential analysis without using hazardous reagents.
- The document outlines sample collection methods using high-volume samplers to collect particulate matter on filters. Filters are extracted ultrasonically to analyze ions.
- Calibration procedures and methods for establishing retention time windows and calibration curves are provided. Precision and accuracy are within 20% for analyzed ions.
Biological Nutrient Removal Applications for Monitoring ORP | YSIXylem Inc.
Biological nutrient removal applications for monitoring oxidation reduction potential in wastewater covers four main topics: the science of ORP/Redox, putting ORP to use, applications and sensor care.
(originally aired 07-26-12)
U.S. EPA and many state agencies are investigating fracking in Marcellus Shale’s impact on environmental water quality. Public outcry has led to drafting legislation. Increased levels of bromide in drinking water systems correlate to higher levels of brominated disinfection byproducts. Trace metals (i.e., arsenic, selenium, lead), important constituents of flowback water, must be accurately determined for regulatory compliance, challenging due to high levels of dissolved salts which can cause physical and spectral interferences. Here, experts discuss monitoring and measuring anion concentrations in water from recycling impoundments, the typical constituents reported for Marcellus Shale fracking operations, flowback water preparation, and ICP-OES and ICP-MS metals analysis.
Many factors impacting the measurement precision of ICP-OES and ICP-MS are still often neglected for everyday operation, however. Sample preparation is one of the factors that play a crucial role in the success of high-quality sample analysis. In this webinar, our experts will discuss sample preparation to: 1) improve analysis precision 2) make difficult samples easy to be analyzed 3) eliminate sample dilution to minimize error introduction.
For more information, please visit here: http://chrom.ms/CtRtKpw
Biological Nutrient Removal Applications for Monitoring ORP | YSIXylem Inc.
Biological nutrient removal applications for monitoring oxidation reduction potential in wastewater covers four main topics: the science of ORP/Redox, putting ORP to use, applications and sensor care.
(originally aired 07-26-12)
U.S. EPA and many state agencies are investigating fracking in Marcellus Shale’s impact on environmental water quality. Public outcry has led to drafting legislation. Increased levels of bromide in drinking water systems correlate to higher levels of brominated disinfection byproducts. Trace metals (i.e., arsenic, selenium, lead), important constituents of flowback water, must be accurately determined for regulatory compliance, challenging due to high levels of dissolved salts which can cause physical and spectral interferences. Here, experts discuss monitoring and measuring anion concentrations in water from recycling impoundments, the typical constituents reported for Marcellus Shale fracking operations, flowback water preparation, and ICP-OES and ICP-MS metals analysis.
Many factors impacting the measurement precision of ICP-OES and ICP-MS are still often neglected for everyday operation, however. Sample preparation is one of the factors that play a crucial role in the success of high-quality sample analysis. In this webinar, our experts will discuss sample preparation to: 1) improve analysis precision 2) make difficult samples easy to be analyzed 3) eliminate sample dilution to minimize error introduction.
For more information, please visit here: http://chrom.ms/CtRtKpw
This lecture is based on previously read lecture "Plant Mineral Analysis", 2012. Some new points were added, especially in LOD/LOQ section. The internal standard calculation was explained. The lecture was presented in the frame of International Course "Crop Production under Saline Stress As A Result Of Climatic Changes", The Faculty of Agriculture, The Hebrew University of Jerusalem.
The Role of IrO2 in Mediating Hole Transfer at the TiO2 Interfacekamatlab
A presentation of key information from our recently published paper:
DOI: 10.1021/jz200852m
Visit our website, KamatLab.com, for the latest news, publications, and research from our group.
HPLC is Analytical technique that is used for separating the mixture of substances,so there is a number of promising application of HPLC-UV here uv detector is used which record the absorbance
Synthesis & Characterization of Fluorescent Silver Nanoparticles stabilized b...IJERA Editor
Synthesis of silver nanoparticles (Ag-NPs) was achieved by a simple green procedure using Tinospora Cordifolia leaf extract as stabilizer/reducing agents. Ag-NPs in the size range of 2–19 nm is obtained by the treatment of aqueous silver ions with leaf extracts of Tinospora Cordifolia. This eco-friendly approach is simple, amenable for large scale commercial production and technical applications. Further, photoluminiscence studies of these Ag-NPs were recorded & suggested that the present particles were suitable for fluorescence emitting probes. These red emitting Ag-NPs exhibited distinct fluorescence properties (both emission and stokeshift).
Introduction to nanoscience and nanotechnologyaimanmukhtar1
Introduction of nanoscience/nanotechnology ,properties/potential applications of nanomaterials and electrodeposition of metal single component and alloy nanowires in AAO template
http://www.surfacetreatments.it/thinfilms
Plasma Etching of Niobium surfaces: Studies on samples and Single-Cell Cavities (AnneMarie Valente - 30')
Speaker: AnneMarie Valente - Jefferson Lab - Newport News (VA) USA | Duration: 30 min.
Abstract
Plasma based surface modification provides an excellent opportunity to eliminate impurities and defects in the penetration depth region of Nb SRF cavity surfaces. It also allows a better control of the final SRF surface as final surface modifications like oxidation or nitridation can be done in the same process cycle.
In the framework of a collaboration between ODU and Jefferson Lab, we are pursuing the use of environmentally friendly dry etching of SRF cavity in an Ar/Cl2 discharge. The experimental conditions in the microwave glow discharge system with a barrel-type reactor have been optimized. The viability of plasma etching as an alternative surface preparation method for bulk Nb surfaces has been demonstrated on flat samples by achieving etching rates comparable to wet processes, such as BCP or EP.
The optimized experimental conditions are now being applied to the preparation of single cell cavities. The geometry of SRF cavities made of bulk Nb defines the use of asymmetric RF discharge configuration for plasma etching. The asymmetry in the surface area of a driven and grounded electrode creates a difference in the voltage drop over the plasma sheath attached to the driven electrode and the plasma sheath attached to the cavity surface. A specially designed single cell cavity with sample holders is used to study these asymmetric discharges. The sample holder ports can be used for both diagnostics and sample etching purposes. The approach is to combine radially and spectrally resolved profiles of optical intensity of the discharge with direct etched surface diagnostics to obtain an optimum combination of etching rates, roughness and homogeneity in a variety of discharge types, conditions and sequences.
Synthesis of Spinel based Catalysts by Wet chemical methods for Colour Remova...PranavkumarRana
The study aimed at color removal and COD degradation of
synthetic wastewater of methylene blue dye via photocatalysis using various spinel catalysts
prepared by different methods. The methylene blue dye with strong azo bond with structure
made up of autochrome and chromophore. The Azo dyes are widely used in textile, paper and
leather industries. The present study is essentially related to the degradation of selected
methylene blue and dye from synthetic dye wastewater however it has been extended to actual
industrial effluents. In order to control wastewater pollution due to dyes the UV-Photocatalytic
degradation technology has been carried out by some researchers using spinel catalysts. Spinel
catalysts are oxides with general formula AB2O4 where A and B are the rare earth, A has
octahedral site and B has tetrahedral site. alkaline earth, alkali metals and transition metal
cations which are expected to be able to overcome the limitations of semiconductors as
photocatalysts.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Low-cost Fiber Optic Chemical Sensor Development for Fishpond ApplicationTELKOMNIKA JOURNAL
In this study, aimed to develop low-cost sensor based on fiber optic to assess ammonia index for fishpond application. Here, the simple design was proposed by using Evanescent wave type to assess ammonia index during acid rain event. The experiment result showed maximum absorption loss with variation ammonia mass 1~5% with wavelength 1310 nm from Optical Light Source (OLS) is 27.56 dBm while Optical Spectrum Analyzer (OSA) reached 25.86 dBm. We had calculated RMSE, MAE, and Percent Error (PE) value both of the device (Low-cost fiber optic chemical sensor and OSA) are 1.692%, 0.916%, and 98.833% respectively. A good result from low cost fiber optic chemical sensor has successful developed with lowest production less than 1,455 USD per-year.
This lecture is based on previously read lecture "Plant Mineral Analysis", 2012. Some new points were added, especially in LOD/LOQ section. The internal standard calculation was explained. The lecture was presented in the frame of International Course "Crop Production under Saline Stress As A Result Of Climatic Changes", The Faculty of Agriculture, The Hebrew University of Jerusalem.
The Role of IrO2 in Mediating Hole Transfer at the TiO2 Interfacekamatlab
A presentation of key information from our recently published paper:
DOI: 10.1021/jz200852m
Visit our website, KamatLab.com, for the latest news, publications, and research from our group.
HPLC is Analytical technique that is used for separating the mixture of substances,so there is a number of promising application of HPLC-UV here uv detector is used which record the absorbance
Synthesis & Characterization of Fluorescent Silver Nanoparticles stabilized b...IJERA Editor
Synthesis of silver nanoparticles (Ag-NPs) was achieved by a simple green procedure using Tinospora Cordifolia leaf extract as stabilizer/reducing agents. Ag-NPs in the size range of 2–19 nm is obtained by the treatment of aqueous silver ions with leaf extracts of Tinospora Cordifolia. This eco-friendly approach is simple, amenable for large scale commercial production and technical applications. Further, photoluminiscence studies of these Ag-NPs were recorded & suggested that the present particles were suitable for fluorescence emitting probes. These red emitting Ag-NPs exhibited distinct fluorescence properties (both emission and stokeshift).
Introduction to nanoscience and nanotechnologyaimanmukhtar1
Introduction of nanoscience/nanotechnology ,properties/potential applications of nanomaterials and electrodeposition of metal single component and alloy nanowires in AAO template
http://www.surfacetreatments.it/thinfilms
Plasma Etching of Niobium surfaces: Studies on samples and Single-Cell Cavities (AnneMarie Valente - 30')
Speaker: AnneMarie Valente - Jefferson Lab - Newport News (VA) USA | Duration: 30 min.
Abstract
Plasma based surface modification provides an excellent opportunity to eliminate impurities and defects in the penetration depth region of Nb SRF cavity surfaces. It also allows a better control of the final SRF surface as final surface modifications like oxidation or nitridation can be done in the same process cycle.
In the framework of a collaboration between ODU and Jefferson Lab, we are pursuing the use of environmentally friendly dry etching of SRF cavity in an Ar/Cl2 discharge. The experimental conditions in the microwave glow discharge system with a barrel-type reactor have been optimized. The viability of plasma etching as an alternative surface preparation method for bulk Nb surfaces has been demonstrated on flat samples by achieving etching rates comparable to wet processes, such as BCP or EP.
The optimized experimental conditions are now being applied to the preparation of single cell cavities. The geometry of SRF cavities made of bulk Nb defines the use of asymmetric RF discharge configuration for plasma etching. The asymmetry in the surface area of a driven and grounded electrode creates a difference in the voltage drop over the plasma sheath attached to the driven electrode and the plasma sheath attached to the cavity surface. A specially designed single cell cavity with sample holders is used to study these asymmetric discharges. The sample holder ports can be used for both diagnostics and sample etching purposes. The approach is to combine radially and spectrally resolved profiles of optical intensity of the discharge with direct etched surface diagnostics to obtain an optimum combination of etching rates, roughness and homogeneity in a variety of discharge types, conditions and sequences.
Synthesis of Spinel based Catalysts by Wet chemical methods for Colour Remova...PranavkumarRana
The study aimed at color removal and COD degradation of
synthetic wastewater of methylene blue dye via photocatalysis using various spinel catalysts
prepared by different methods. The methylene blue dye with strong azo bond with structure
made up of autochrome and chromophore. The Azo dyes are widely used in textile, paper and
leather industries. The present study is essentially related to the degradation of selected
methylene blue and dye from synthetic dye wastewater however it has been extended to actual
industrial effluents. In order to control wastewater pollution due to dyes the UV-Photocatalytic
degradation technology has been carried out by some researchers using spinel catalysts. Spinel
catalysts are oxides with general formula AB2O4 where A and B are the rare earth, A has
octahedral site and B has tetrahedral site. alkaline earth, alkali metals and transition metal
cations which are expected to be able to overcome the limitations of semiconductors as
photocatalysts.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Low-cost Fiber Optic Chemical Sensor Development for Fishpond ApplicationTELKOMNIKA JOURNAL
In this study, aimed to develop low-cost sensor based on fiber optic to assess ammonia index for fishpond application. Here, the simple design was proposed by using Evanescent wave type to assess ammonia index during acid rain event. The experiment result showed maximum absorption loss with variation ammonia mass 1~5% with wavelength 1310 nm from Optical Light Source (OLS) is 27.56 dBm while Optical Spectrum Analyzer (OSA) reached 25.86 dBm. We had calculated RMSE, MAE, and Percent Error (PE) value both of the device (Low-cost fiber optic chemical sensor and OSA) are 1.692%, 0.916%, and 98.833% respectively. A good result from low cost fiber optic chemical sensor has successful developed with lowest production less than 1,455 USD per-year.
The slides covers brief description of ion exclusion chromatography. i hope the slides will be helpful
for any further details you can contact me through email.
mail id - sobhigaba@gmail.com
An ideal I.S.E. consists of a thin membrane across which only the
intended ion can be transported.
The transport of ions from a high conc. to a low one through a selective binding with some sites within the membrane creates a
A report for my Environmental Management for Food Industries Class
This discussed the significance of trace and heavy metals present in wastewater and also the methods that can be used to lessen and remove them.
Epcon is One of the World's leading Manufacturing Companies.EpconLP
Epcon is One of the World's leading Manufacturing Companies. With over 4000 installations worldwide, EPCON has been pioneering new techniques since 1977 that have become industry standards now. Founded in 1977, Epcon has grown from a one-man operation to a global leader in developing and manufacturing innovative air pollution control technology and industrial heating equipment.
WRI’s brand new “Food Service Playbook for Promoting Sustainable Food Choices” gives food service operators the very latest strategies for creating dining environments that empower consumers to choose sustainable, plant-rich dishes. This research builds off our first guide for food service, now with industry experience and insights from nearly 350 academic trials.
"Understanding the Carbon Cycle: Processes, Human Impacts, and Strategies for...MMariSelvam4
The carbon cycle is a critical component of Earth's environmental system, governing the movement and transformation of carbon through various reservoirs, including the atmosphere, oceans, soil, and living organisms. This complex cycle involves several key processes such as photosynthesis, respiration, decomposition, and carbon sequestration, each contributing to the regulation of carbon levels on the planet.
Human activities, particularly fossil fuel combustion and deforestation, have significantly altered the natural carbon cycle, leading to increased atmospheric carbon dioxide concentrations and driving climate change. Understanding the intricacies of the carbon cycle is essential for assessing the impacts of these changes and developing effective mitigation strategies.
By studying the carbon cycle, scientists can identify carbon sources and sinks, measure carbon fluxes, and predict future trends. This knowledge is crucial for crafting policies aimed at reducing carbon emissions, enhancing carbon storage, and promoting sustainable practices. The carbon cycle's interplay with climate systems, ecosystems, and human activities underscores its importance in maintaining a stable and healthy planet.
In-depth exploration of the carbon cycle reveals the delicate balance required to sustain life and the urgent need to address anthropogenic influences. Through research, education, and policy, we can work towards restoring equilibrium in the carbon cycle and ensuring a sustainable future for generations to come.
Artificial Reefs by Kuddle Life Foundation - May 2024punit537210
Situated in Pondicherry, India, Kuddle Life Foundation is a charitable, non-profit and non-governmental organization (NGO) dedicated to improving the living standards of coastal communities and simultaneously placing a strong emphasis on the protection of marine ecosystems.
One of the key areas we work in is Artificial Reefs. This presentation captures our journey so far and our learnings. We hope you get as excited about marine conservation and artificial reefs as we are.
Please visit our website: https://kuddlelife.org
Our Instagram channel:
@kuddlelifefoundation
Our Linkedin Page:
https://www.linkedin.com/company/kuddlelifefoundation/
and write to us if you have any questions:
info@kuddlelife.org
UNDERSTANDING WHAT GREEN WASHING IS!.pdfJulietMogola
Many companies today use green washing to lure the public into thinking they are conserving the environment but in real sense they are doing more harm. There have been such several cases from very big companies here in Kenya and also globally. This ranges from various sectors from manufacturing and goes to consumer products. Educating people on greenwashing will enable people to make better choices based on their analysis and not on what they see on marketing sites.
Climate Change All over the World .pptxsairaanwer024
Climate change refers to significant and lasting changes in the average weather patterns over periods ranging from decades to millions of years. It encompasses both global warming driven by human emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. While climate change is a natural phenomenon, human activities, particularly since the Industrial Revolution, have accelerated its pace and intensity
Characterization and the Kinetics of drying at the drying oven and with micro...Open Access Research Paper
The objective of this work is to contribute to valorization de Nephelium lappaceum by the characterization of kinetics of drying of seeds of Nephelium lappaceum. The seeds were dehydrated until a constant mass respectively in a drying oven and a microwawe oven. The temperatures and the powers of drying are respectively: 50, 60 and 70°C and 140, 280 and 420 W. The results show that the curves of drying of seeds of Nephelium lappaceum do not present a phase of constant kinetics. The coefficients of diffusion vary between 2.09.10-8 to 2.98. 10-8m-2/s in the interval of 50°C at 70°C and between 4.83×10-07 at 9.04×10-07 m-8/s for the powers going of 140 W with 420 W the relation between Arrhenius and a value of energy of activation of 16.49 kJ. mol-1 expressed the effect of the temperature on effective diffusivity.
Willie Nelson Net Worth: A Journey Through Music, Movies, and Business Venturesgreendigital
Willie Nelson is a name that resonates within the world of music and entertainment. Known for his unique voice, and masterful guitar skills. and an extraordinary career spanning several decades. Nelson has become a legend in the country music scene. But, his influence extends far beyond the realm of music. with ventures in acting, writing, activism, and business. This comprehensive article delves into Willie Nelson net worth. exploring the various facets of his career that have contributed to his large fortune.
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Introduction
Willie Nelson net worth is a testament to his enduring influence and success in many fields. Born on April 29, 1933, in Abbott, Texas. Nelson's journey from a humble beginning to becoming one of the most iconic figures in American music is nothing short of inspirational. His net worth, which estimated to be around $25 million as of 2024. reflects a career that is as diverse as it is prolific.
Early Life and Musical Beginnings
Humble Origins
Willie Hugh Nelson was born during the Great Depression. a time of significant economic hardship in the United States. Raised by his grandparents. Nelson found solace and inspiration in music from an early age. His grandmother taught him to play the guitar. setting the stage for what would become an illustrious career.
First Steps in Music
Nelson's initial foray into the music industry was fraught with challenges. He moved to Nashville, Tennessee, to pursue his dreams, but success did not come . Working as a songwriter, Nelson penned hits for other artists. which helped him gain a foothold in the competitive music scene. His songwriting skills contributed to his early earnings. laying the foundation for his net worth.
Rise to Stardom
Breakthrough Albums
The 1970s marked a turning point in Willie Nelson's career. His albums "Shotgun Willie" (1973), "Red Headed Stranger" (1975). and "Stardust" (1978) received critical acclaim and commercial success. These albums not only solidified his position in the country music genre. but also introduced his music to a broader audience. The success of these albums played a crucial role in boosting Willie Nelson net worth.
Iconic Songs
Willie Nelson net worth is also attributed to his extensive catalog of hit songs. Tracks like "Blue Eyes Crying in the Rain," "On the Road Again," and "Always on My Mind" have become timeless classics. These songs have not only earned Nelson large royalties but have also ensured his continued relevance in the music industry.
Acting and Film Career
Hollywood Ventures
In addition to his music career, Willie Nelson has also made a mark in Hollywood. His distinctive personality and on-screen presence have landed him roles in several films and television shows. Notable appearances include roles in "The Electric Horseman" (1979), "Honeysuckle Rose" (1980), and "Barbarosa" (1982). These acting gigs have added a significant amount to Willie Nelson net worth.
Television Appearances
Nelson's char
Summary of the Climate and Energy Policy of Australia
Monitoring of inorganic ions
1. Monitoring of Inorganic Ions in Ambient Air
Mr. S. D. Joshi
Scientist
Air Pollution Control Division, NEERI, Nagpur - 440020
Introduction
The air besides containing gaseous pollutants like S02, NOx, CO, HC also
contains particulate matter which is made up of complex organic compounds,
inorganic elements and their oxides and secondary particulates viz, sulphate,
nitrate etc. These secondary particulates are formed from their precursors in
presence of sunlight humidity and metal ion species by oxidation or reduction
processes. The acid precursors viz. sulfate and nitrate, and chloride require
more concern as these have deleterious effects on aquatic and forest eco-
systems and are potentially harmful for a variety of building materials, accelerate
corrosion of metals, damage sculptures and cause chronic respiratory problems
in human beings. In view of possible large social, economic, ecological and
aesthetic value, it has become important to analyse these pollutants in the
ambient air.
These particulates are emitted in the atmosphere by different
anthropogenic and natural sources. Sulphate (SO4-) is formed in the
atmosphere by reduction or oxidation in presence of hydroxy! ion (OH"). The
main sources of sulfur oxides are power houses, sulphuric acid, petroleum
industries, oil refineries, coal burning and domestic use of fuels. Acid
manufacturing, automobile exhaust, explosive industry, fuel burning etc. are the
main sources of nitrogen oxides. Chloride occurs predominantly in coastal cities.
Other sources of chloride are coal burning, waste incineration, automobile
exhaust, burning of chlorinated hydrocarbons. Fluoride is emitted in the
atmosphere by fertiliser industry, aluminium industry, steel making and acid
making industries.
2. Analytical Techniques
Different methods are available for the analysis of anions. The
conventional methods, viz., titrimetric, colorimetric, spectrophotometric,
gravimetric and ion selective electrode methods though commonly used, are
ion specific, time consuming and less sensitive. Ion Chromatography (IC) is the
only instrumental technique which can be used for rapid, sequential analysis of
different anions simultaneously.
Ion Chromatography
Chromatography encompasses wide range of techniques of separation of
the components of a mixture as a result of differential migration of the component
molecules between stationary phase and mobile phase. It was Hamish, Small of
DOW chemical corporation whose pioneering work in mid seventies in the
analysis of multiple -ion mixture developed into, 'Ion Chromatography" Ion
chromatograph provides a single instrumental technique for rapid sequential
analysis of different anions present in a sample. Ion chromatograph eliminates
the need to use hazardous reagents and it effectively distinguishes among the
halides (Cr,F~) and the oxides (NO3", SO4"). For ambient air monitoring, IC is
the most suitable technique though it is expensive. The anions SO4", NO3", CI",
F" are being monitored in ambient air using IC 2000i/SP and DX-100 models
under NAQM project, NEERI.
Several approaches have been initiated to solve the problem of separation
and detection of ions either independently or in integrated fashion. Three major
approaches are:
i) suppressed ion chromatography
ii) non-suppressed ion chromatography and
iii) indirect detection ion chromatography
3. Suppressed Ion chromatography
In the group of separation techniques employing ionic interactions ion
exchange is the oldest one. The separation is carried out with the packing that
possess charge bearing functional groups. The most common retention
mechanism is simple ion exchange of sample ions X and mobile phase ion Y
with the charged groups R of the stationary phase.
X" + R+
Y_
Y" + R+
X" anion exchange
X+
+ R"Y+
Y+
+ R"X+
cation exchange
For anion exchange separation the sample ions X" are in competition with
the mobile phase ions Y" for the ionic sites R+
of the ion exchanger. Sample ions
that interact weakly with the ion exchanger, in the presence of competing mobile
phase ion will be retained on the column for a shorter duration whereas sample
ion interacting strongly to with the ion exchanger will be retained for larger.
Conductivity being universal property of ionic species in solution, showing
simple dependence on the concentration of ions, has been considered to solved
detection problem since long. However, in ion exchange separation conductivity
response is masked by the mobile phase electrolyte. This problem was tackled
by employing a novel combination of ion exchange columns to remove the
background electrolyte leaving only the ionic solute of interest as conducting
species in the column effluent.
The second column called the stripper or the suppresser complicates the
use of ion chromatography. The stripper column needs periodic regeneration
and furthermore ion exclusion effects and some band broadening in the
suppresser column deteriorates the analysis.
To optimise the regeneration and chromatographic efficiency of
conventional suppressor column, the relative volumes and specific ion exchange
capacities of separator and stripper columns are adjusted. For good
chromatographic efficiency volume ratio of stripper and separator column is kept
iii
4. low unity being desirable but values upto 10 acceptable. Regeneration
requirements are minimised by using low capacity pellicular particles or surface
modified resins in separating columns, low ionic strength mobile phase, small
sample size and conventional high capacity porous ion exchange resin in the
stripper. Typical low capacity separator column can be used alongwith
conventional high capacity suppresser column for 8 to 10 hours without requiring
regeneration. Automatic - regeneration feature in commercial instruments
further simplify the analysis. However suppresor should not react with the
sample ions in a way that would remove them from the eluant or reduce their
conductivities or retain them permanently undergoing irreversible changes.
Non Suppressed Ion Chromatography
The ion chromatographic systems with suppresser columns are generally
dedicated and relatively costly. Analysis by non-suppressed systems depends
on existence of a significant measurable difference between sample ions and the
prevailing eiuent ions. For improving sensitivity low capacity exchanges and
proper displacing ions are required. Low capacity exchanger match the low ionic
strength eiuent employed, which enable detection of small amounts of samples
and proper displacing ions can display a useful difference in equivalent
conductance in comparison with common inorganic ions. Low capacity micro
porous anion exchange resin also have been developed for the separation of
inorganic anions. The resins used macro reticular cross-linked polystyrene
beads as substrate. The conductivity detector used for this method requires a
large electronic offset range for nulling the background conductivity of the eiuent
and small cell currents to minimise heat dissipation in the cell and resulting
baseline drift and noise. This detector given best results when used with low
background conductivity of the eiuent and fine temperature stability.
Indirect Detection Ion Chromatography
Many inorganic ions display strong absorbance in UV region but at
wavelengths that were previously inaccessible to liquid chromatography
photometers. With the development of UV detectors that reach down to 190 nm.
These ions are easily amenable to sensitive monitoring and determination. Direct
iv
5. UV absorbance has been coupled with several separation modes for variety of
samples. However, the major drawback of these methods is the low sensitivity
even after employing high purity solutes to minimise background absorbance.
Recently the method of indirect detection is gaining applications.
Generally in ion exchange or ion pair separation ultraviolet detector is used in
conjunction with mobile phases with very low absorbance at the monitoring
wavelength.
The sample contains the chromospheres and when they elute and pass
through the detector, absorption of light takes place and positive peak is
recorded.
Generally low capacity ion exchange columns are employed as separators
and an aqueous solutions of potassium hydrogen phthalate (10~4
to 10"3
M) as
mobile phase. This salt gives suitable absorption at the wavelength 265 mm.
The choice of the mobile phase and its strength is decided by the anions of
interest and analysis time.
A large number of organic and and inorganic ions have been studied by
this technique. Analogous schemes for cation analysis have also been reported.
Simultaneous analysis of anions and cations in a single chromatogram also can
be done by this system.
Refractive index detector also has been used in this indirect mode. Both
UV & Rl methods are more sensitive than conductivity detection and they give
less baseline noise.
Interference : Any substance that has retention time coinciding with that
of any anion to be determined will interference. For example relatively high
concentrations of low molecular weight organic acids interfere with the
determination of chloride and fluoride. Sample dilution over comes many
6. interferences. Spurious peaks may result from contaminants in reagent water,
glassware or sample processing apparatus.
Minimum Detectable Limit
The minimum detectable concentration of an anion is a function of sample
size and conductivity scale used. Generally, minimum detectable concentrations
are near 0.1 mg/l for Br, CI", NO3-, N02", P04
3
" and S04
2
" with a 25 pi loop
and a 10 pS/cm full scale setting on the conductivity detector.
Air Monitoring/Sampling Collection
For ambient air anion sampling and analytical technique being used for
these pollutants require a large volume of air to be sampled in order to reach
needed detections limits. This has been accomplished utilising the high volume
(1400 Ipm) air sampler for the collection of total suspended particulate matter.
While for respirable suspended particulate matter, respirable dust sampler
is used. This sampler can be adapted with an optional PM-10 aerodynamic
aerosol inlet cut-point design which is insensitive to small variations in sampling
flow rate.
Preparation of Sample Filter
The filter papers are dried in desiccators for hours before, use. To ensure
acceptable filters, they are extracted with water and extracts are analysed by ion
chromatography. A filter blank of less than 0.1 pg per filter is considered
acceptable for field use.
Calibration of Sampling System
Each sampler is to be calibrated i) when new ii) after major repairs or
maintenance iii) whenever any audit point deviates from the calibration curve by
more than 7% iv) when a different sample collection media, other than that which
the sampler was originally calibrate to will be used for sampling, v) before and
after each test series.
vi
7. Construct a best fit curve for the points generated and use this relationship
for future work employing the flow sensor device.
Sample Retrieval
At the end of the desired sampling period the power is turned off.
Carefully remove the sampling head containing the filter. Remove filter from the
upper chamber using clean, teflon tipped forceps. Fold the filter in half twice
(Sampled side inward) and place it in an labeled envelope. These filters should
stored in dessicator containing dry silica gel. If the time span between sample
collection and laboratory analysis is to exceed 24 hour samples must be kept
refrigerated at 4°C. At least on field filter should be returned to the laboratory
with each group of samples. A field blank is treated exactly as a sample except
that no air is drawn throughout the filter.
Analysis
Reagents : Deionised or distilled water free from interferences at the
minimum detection limit of each constituent.
Eluant Solution : Eluant solution is a mixture of 1.7 mm sodium
bicarbonate and 1.8 mm Sodium Carbonate.
Regenerant Solution
Regenerant solution is all glass double distilled water for continous
regeneration.
Standard Anion Solution
Prepare a series of standard anion solutions by weighing the inducted
amount of salt, dried to a constant weight at 105°C to 1000 ml. Store in plastic
bottles in a refrigerator. These solutions are stable for at least one month. Verify
stability.
vii
8. Combine Working Standard Solution
Prepare a combined working standard solution by mixing appropriate
quantity of stock solution and store in plastic bottle protected from light. Prepare
fresh daily.
Ultrasonic Extraction Method
The extraction of anions is carried out by ultrasonic compact cleaner
model SW 45 (Toshniwal). The tank volume of extractor is 4.5 lits. It has a
sonifer cell disrupter .40 KHz power ultrasonic generator capable of dialing
150/130 w accurately with 127 cm horn distrupter sonabox.
From the exposed filter paper 18 circles of 1.5 cm diameter each were
taken by punching with steel punch (area 31.8 cm2
) in a clean 100 ml beaker. To
these circles 20 ml deionised water was added and extracted for 5 min in
ultrasonicator. The extract was vacuum filtered with the help of G4 sintered glass
crucible in a clean plastic bottle. Again 20 ml water was added and extraction
was done for 10 min. The filtrate was collected in same bottle. The extraction
procedure was repeated third time for 15 minutes. The extracted samples were
stored in fridge till analysis.
Calibration Curve
Prepare standards of different concentration by mixing known volume of
different ions. Inject standards containing single anion or a mixture and
determine approximate retention time. Inject atleast three different concentrations
for each anion to be measured and construct a calibration curve by plotting peak
height or area against concentration on linear graph paper. Recalibrate
whenever detector setting is changed. Record the peak height or area and
retention time for calculation of the calibration factor CF.
Calibration Factor CF =
Total area of peak
Mass injected (in microgram)
9. if the percent relative standard deviation (% RSD) of the calibration factor is less
than 20% over the working range, linearity through the origin can be assumed,
and average calibration factor can be used in place of a calibration curve.
The working calibration curve or calibration factor must be verified on each
working day by the injection of one or more calibration standards. If the response
factor for any analyte varies from the predicted response by more than + 20% a
new calibration curve must be prepared for that analyte. Calculate the percent
variance by the following equation-
Percent variance = [(R2 -Ri)/R<|] X 100
Before analysis can be performed the retention time windows must be
established for each analyte. Make three injections of the standard containing all
compounds for retention time window determination. The retention time window
is defined as the plus or minus three times the standard deviation of the absolute
retention times for each standard.
System Equillibration
Turn on ion chromatograph and adjust eluant flow rate. Adjust detector to
desired setting and let system come to equilibrium (20 to 30 min). A stable
baseline indicates equilibrium conditions. Adjust detector offset to zero out eluant
conductivity; with fibre or membrane suppressor adjust the regeneration flow rate
to maintain stability usually 2 to 3 mL/min.
Ion Chromatography with Conductivity Detector
Under the calibration procedures (external)the % RSD of the calibration
factor should be <20% over the linear working range of a five point calibration
curve.
Under the calibration procedures (external) daily working calibration curve
for each analyte should not vary from the predicted response by more than +
20%.
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10. For each analyte the retention time window must be established, verified
on a daily basis and established for each analyte throughout the course of a 72
hour period.
For each analyte the mid level standard must fall within the retention time
window on a daily basis as a qualitative performance evaluation of the IC system.
The surrogate standard recovery must not deviate by more than 20%.
Calibration
The stock standard solutions were prepared by adding exactly weighed
known amount of compound to a one litre volumetric flask and voiume was made
up by deionised water. A series of different concentrations of standards were
prepared by diluting stock standard solution.
Retention Time
The retention time is the time required for complete elution of a component
from the point of injection of sample. The retention time windows for each analyst
was determined. The retention time window is defined as plus or minus three
times the standard deviation of the absolute retention times for each standard.
Range and Sensitivity
The minimum detectable limit for chloride ion at sensitivity 100 is 2.44 pg.
The minimum detectable concentration of chloride ion for particulates collected
on one glass fiber filter of approximately 400 cm2
is 0.064 pg if 480 m3
of air are
sampled in the ambient atmosphere. The minimum detectable limit for SO4 is
3 pg for fluoride 0.4 pg and for nitrate 0.5 pg at sensitivity 100 on 2000 i/SP
Dionex ion chromatograph.
Precision and Accuracy
The blank fiber filter paper was spiked by known concentration of anions
and extracted ultrasonically. The relative standard deviation (RSD) for 3
ultrasonic extract for SO4 was ±1.35. For nitrate 5.54% for chloride 4.23% and for
11. fluoride 4.5%. The percentage recovery for SO4 is 98.02 for chloride 97.4, for
nitrate 98.0 and for fluoride 95.0.
Similarly the exposed filter papers were also spiked by known
concentration of anions. The RSD for 2 ultrasonic extract for sulphate was 1.44
for nitrate 5.8 for chloride 5.2 & for fluoride 5.5. The percentage recovery for SO4
is 97.01 for chloride 95.2 for nitrate 95 and for fluoride 90.58%.
Calculations
The concentration of different ions is calculated in ug/m3
concentration = peak height concentration Volumeof Total area of 1
(ug/m3
) of sample (cm) X of standard (ug) X sample X filter paper(cm2
) X
peak height of Area taken for volume of
standard (cm) extraction(cm2
) air (m3
)
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