A pH meter measures the concentration of hydrogen ions in a solution to determine if it is acidic or alkaline. It works by measuring the potential difference between a glass electrode that senses the hydrogen ions and a reference electrode in contact with a reference solution. The glass electrode contains a special glass bulb that allows hydrogen ions to interact with it, changing the electrochemical potential. This potential difference is measured by the pH meter and converted to a pH value. A silver chloride electrode is commonly used as the reference electrode due to its stable and reproducible reaction.
Introduction and principle of glc, hplc
columns of hplc
columns of glc
detectors of glc
detectors of hplc
chromatography
classification of chromatography
gas liquid chromatography
high performance liquid chromatography
Introduction and principle of glc, hplc
columns of hplc
columns of glc
detectors of glc
detectors of hplc
chromatography
classification of chromatography
gas liquid chromatography
high performance liquid chromatography
Gas chromatography-mass spectrometry (GC-MS) is the synergistic combination of two analytical method to separate and identify different substances within a test sample.
Gas chromatography separates the components of a mixture in time.
Mass spectrometer provides information that aids in the identification and structural elucidation of each component.
It is an important tool in biochemical research. Which through rapid spinning imposes high centrifugal forces on suspended particles, or even molecules in solution, and causes separations of such matter on the basis of differences in weight.
Isoelectric focusing electrophoresis- Principle , procedure and applicationsJaskiranKaur72
IEF separates amphoteric compounds, such as proteins, with increased resolution in a medium possessing a stable pH gradient. The protein becomes “focused” at a point on the gel as it migrates to a zone where the pH of the gel matches the protein's pI. At this point, the charge of the protein becomes zero and its migration ceases.
Gas chromatography-mass spectrometry (GC-MS) is the synergistic combination of two analytical method to separate and identify different substances within a test sample.
Gas chromatography separates the components of a mixture in time.
Mass spectrometer provides information that aids in the identification and structural elucidation of each component.
It is an important tool in biochemical research. Which through rapid spinning imposes high centrifugal forces on suspended particles, or even molecules in solution, and causes separations of such matter on the basis of differences in weight.
Isoelectric focusing electrophoresis- Principle , procedure and applicationsJaskiranKaur72
IEF separates amphoteric compounds, such as proteins, with increased resolution in a medium possessing a stable pH gradient. The protein becomes “focused” at a point on the gel as it migrates to a zone where the pH of the gel matches the protein's pI. At this point, the charge of the protein becomes zero and its migration ceases.
Slides giving an overview on pH and its measurement.
Contains information about pH meters, its calibration, maintenance , types of ph electrode and modern definition of pH
A separation technique in which the mobile phase is a gas. Gas chromatography is always carried out in a column.
Separating mixtures of gases or volatile materials based primarily on their physical properties.
X-ray crystallography is a technique used for determining the atomic and molecular structure of a crystal, in which the crystalline atoms cause a beam of incident X-rays to diffract into many specific directions.
HPLC Principle,Instrumentation and ApplicationAlakesh Pradhan
HPLC Chromatography and its principle
Liquid chromatography
High Performance Liquid Chromatography ( HPLC )
The components of the high performance liquid chromatograph (HPLC).
The separation process.
The chromatogram
Potentiometry is the field of electro-analytical chemistry in which potential is measured without current flow.
It is a method of analysis in which we determine the concentration of solute in solution and the potential difference between two electrodes.
ESTIMATION OF THE RATE OF REACTION WILL BE DONE BASED ON THE POTENTIAL DIFFERENCE BETWEEN REFERENCE AND INDICATOR ELECTRODE. THE POTENTIAL OF THE REFERENCE ELECTRODE IS STABLE WHERE AS THE POTENTIAL OF THE INDICATOR ELECTRODE VARIES WITH THE POTENTIAL OF THE SOLUTION IN WHICH IT IS PLACED
Segmentation in Drosophila melanogaster Shreya Ahuja
All human beings, no matter how different we look, have a certain basic body plan established in us (for instance, all of us have our heads are placed right above our shoulders with arms stretching out from either side). Drosophila is no exception. This presentation talks about establishment of the body plan in Drosophila, how and when the different Segmentation Genes are expressed in Drosophila to give rise to its segmented body pattern.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
This pdf is about the Schizophrenia.
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Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
2. • A pH meter provides a value as to how acidic or alkaline a liquid is. The basic principle of the pH meter is to measure the
concentration of hydrogen ions. Acids dissolve in water forming positively charged hydrogen ions (H+). The greater this
concentration of hydrogen ions, the stronger the acid is. Similarly alkali or bases dissolve in water forming negatively
charged hydrogen ions (OH-). The stronger a base is the higher the concentration of negatively charged hydrogen ions
there are. The amount of these hydrogen ions present solution is dissolved in some amount of water determines the pH.
• A pH value of 7 indicates a neutral solution. Pure water should have a pH value of 7. Now pH values less than 7 indicate an
acidic solution while a pH value greater than 7 will indicate an alkaline solution. A solution with pH value of 1 is highly acidic
and a solution of pH value of 14 is highly alkaline.
WHAT IS pH??
3. • A pH meter will be made up of a probe, which itself is made up of two electrodes. This
probe passes electrical signals to a meter which displays the reading in pH units. The
glass probe has two electrodes because one is a glass sensor electrode and the other is
a reference electrode. Some pH meters do have two separate probes in which case one
would be the sensor electrode and the other the reference point.
• Both electrodes are hollow bulbs containing a potassium chloride solution with a silver
chloride wire suspended into it. The glass sensing electrode has a bulb made up of a very
special glass coated with silica and metal salts. This glass sensing electrode measures
the pH as the concentration of hydrogen ions surrounding the tip of the thin walled
glass bulb. The reference electrode has a bulb made up of a non-conductive glass or
plastic.
• When one metal is brought in contact with another, a voltage difference occurs due to
their differences in electron mobility. Similar is the case with two liquids. A pH meter
measures essentially the electro-chemical potential between a known liquid inside the
glass electrode (membrane) and an unknown liquid outside. Because the thin glass bulb
allows mainly the agile and small hydrogen ions to interact with the glass, the glass
electrode measures the electro-chemical potential of hydrogen ions or the potential of
hydrogen. To complete the electrical circuit, also a reference electrode is needed.
BASIC PRINCIPLE OF A pH METER
GLASS BULB
4. A typical modern pH probe is a combination electrode, which combines both the glass
and reference electrodes into one body. The combination electrode consists of the
following parts :
• A sensing part of electrode, a bulb made from a specific glass
• Internal electrode, usually silver chloride electrode or calomel electrode
• Internal solution, usually a pH=7 buffered solution of 0.1 mol/L KCl for pH
electrodes
• Reference electrode, usually the same type as 2
• Reference internal solution, usually 0.1 mol/L KCl
• Junction with studied solution, usually made from ceramics or capillary
with asbestos or quartz fiber.
• Body of electrode, made from non-conductive glass or plastics.
The bottom of a pH electrode balloons out into a round thin glass bulb. The pH
electrode is best thought of as a tube within a tube. The innermost tube (the inner
tube) contains an unchanging 1×10−7 mol/L HCl solution. Also inside the inner tube is the
cathode terminus of the reference probe. The anodic terminus wraps itself around the
outside of the inner tube and ends with the same sort of reference probe as was on the
inside of the inner tube. It is filled with a reference solution of 0.1 mol/L KCl and has
contact with the solution on the outside of the pH probe by way of a porous plug that
serves as a salt bridge.
HOW IS THE pH PROBE DESIGNED??
5. • A silver chloride electrode is a type of reference electrode, commonly used in electrochemical measurements. For
example, it is usually the internal reference electrode in pH meters. The reaction is between the silver metal (Ag) and
its salt — silver chloride (AgCl, also called silver(I) chloride).
The corresponding equations can be presented as follows:
• This reaction is characterized by fast electrode kinetics, meaning that a sufficiently high current can be passed
through the electrode with the 100% efficiency of the redox reaction (dissolution of the metal or cathodic deposition
of the silver-ions). The reaction has been proved to obey these equations in solutions of pH values between 0 and 13.5.
SILVER CHLORIDE ELECTRODE
6. The pH meter measures the potential difference and its changes across the glass membrane. The potential difference must
be obtained between two points; one is the electrode contacting the internal solution. A second point is obtained by
connecting to a reference electrode, immersed in the studied solution. Often, this reference electrode is built in the glass
electrode (a combination electrode), in a concentric double barrel body of the device.
WORKING OF A pH METER
7. • Ag/AgCl | HCl | glass || probed solution | reference electrode)
• AgCl(s) | KCl(aq) || 1×10-7M H+ solution || glass membrane || Test Solution || ceramic junction || KCl(aq) | AgCl(s) | Ag(s)
• The potential difference relevant to pH measurement builds up across the outside glass/solution interface marked ||
• The bulb is sealed to a thicker glass or plastic tube, and filled, for example, with a solution of HCl (0.1 mol/dm3). In this solution is
immersed a silver/silver chloride electrode with a lead to the outside through a permanent hermetic seal. The filling solution has
constant Cl- concentration, which keeps the Ag/AgCl inner electrode at fixed potential.
• The pH sensing ability of the glass electrode stems from the ion exchange property of its glass membrane.
• Glass is mostly amorphous silicon dioxide, with embedded oxides of alkali metals. When the surface of glass is exposed to water,
some Si–O- groups become protonated
• Si-O- + H3O+ ≡ Si-O-H+ + H2O (2)
• The exchange of hydronium (or written as proton, H+) between the solid membrane and the surrounding solution, and the
equilibrium nature of this exchange, is the key principle of H3O+ sensing. As with any interface separating two phases between
which ionic exchange equilibrium is established, the glass membrane/solution interface becomes the site of a potential difference
• Eglass electrode = E ‘ + RT/2.303F log a(H3O+)
Where E’ represents the sum of the constant offset potentials of the inner glass surface/solution and the two
Ag/AgCl electrodes. At 30°C the potential of the glass membrane changes by about 60 mV for each one unit of pH