This document summarizes a seminar presentation on refractometry. It discusses the principles and instrumentation of refractometry, including Abbe, immersion, and Pulfrich refractometers. Factors affecting refractive index measurements are described, such as temperature, pressure, wavelength of light. Applications of refractometry include identification of organic compounds, determination of solution concentrations and purity, as well as uses in gemology, veterinary medicine, and other fields. Advances in refractometry include techniques for colloidal dispersions and using it to measure immunoglobulin status in dairy calves.
The refractive index or index of refraction of a substance is a measure of the speed of light in that substance. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium.
The refractive index or index of refraction of a substance is a measure of the speed of light in that substance. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium.
A method of obtaining an Infrared spectrum by measuring the interferogram of a sample using an interferometer, then performing a Fourier Transform upon the interferogram to obtain the spectrum.
This article illustrates the principle and working of Colorimeter and Photometer and how absorbance, transmittance and light intensity can be measured.
Optical Rotation and Polarimeter by Dr. A. AmsavelDr. Amsavel A
Isomers and enantiomers
Specific Optical Rotation
Polarimeter
Instrumentation and Operation
Factors affect the Optical Rotation
Calibration
Application Specifically Pharmaceutical Industries
What is Gravimetric analysis, stepes invloved in gravimetry, Filteration medium in gravimetry, gravimetric factor, application, organic and inorganic prepecating agents
Ultraviolet-visible (UV-Vis) spectrophotometry is a technique used to measure light absorbance across the ultraviolet and visible ranges of the electromagnetic spectrum. When incident light strikes matter it can either be absorbed, reflected, or transmitted. The absorbance of radiation in the UV-Vis range causes atomic excitation, which refers to the transition of molecules from a low-energy ground state to an excited state.
A method of obtaining an Infrared spectrum by measuring the interferogram of a sample using an interferometer, then performing a Fourier Transform upon the interferogram to obtain the spectrum.
This article illustrates the principle and working of Colorimeter and Photometer and how absorbance, transmittance and light intensity can be measured.
Optical Rotation and Polarimeter by Dr. A. AmsavelDr. Amsavel A
Isomers and enantiomers
Specific Optical Rotation
Polarimeter
Instrumentation and Operation
Factors affect the Optical Rotation
Calibration
Application Specifically Pharmaceutical Industries
What is Gravimetric analysis, stepes invloved in gravimetry, Filteration medium in gravimetry, gravimetric factor, application, organic and inorganic prepecating agents
Ultraviolet-visible (UV-Vis) spectrophotometry is a technique used to measure light absorbance across the ultraviolet and visible ranges of the electromagnetic spectrum. When incident light strikes matter it can either be absorbed, reflected, or transmitted. The absorbance of radiation in the UV-Vis range causes atomic excitation, which refers to the transition of molecules from a low-energy ground state to an excited state.
The digital refractometers have an extensive range of scale types for use in a wide variety of applications. The equipment is sturdy and has a long battery life. For More Information Please Logon http://goo.gl/Qyx5CM
Presented By :- Raghav Sharma
Class :- M. Pharm, 1st sem.
Department :- Pharmaceutics
Institute :- Parul Institute of Pharmacy
Content :-
Instrumentation and working of flame photometry
Flame atomizer
Nebulizer
Atomizer burner
Monochromator
Detector
Amplifier
Advantages
Disadvantages
Reference
TO STUDY THE PURITY OF DIFFERENT HOME OILS USING REFRACTIVE INDEXNeha Mannewar
The usual method of the determination of the refractive index depend upon the bending of the light on passing through the portion of the substance having flat surface.The angle of total reflection is measured.This is illustrated by the Abbe refractrometer.Other method depend upon the optical effect produce when light passes through portion of the subsatnce having closed surface.This is the principal incolved inmethods for obtaining refractive index b means of microscope.
The method to be described is based upon later principle and may be called as “Refractroscopic”method to distinguish it from method using refractrometer ,since the opical effect is not measured
The acid value (AV) of edible vegetable oils provides important information about the quality and the degree of purity of oil during processing and storage. The present study was designed to correlate the refractive index (RI) obtained using SPR with AV obtained using the official AOCS method (Cd 3a-63).
This is mainly used to determine the scattering of the light by the suspended particles present in the sample solution. The instruments used for the measurement of the scattering are called nephelometer and turbidimeters. The choice between the nephelometry and turbidimetry depends upon the fraction of light scattered. This light scattering by the particles which are present in the colloids is known as the Tyndall affect.
Nephelometry is the measurement of the scattered light by the suspended particles at right angles to the incident beam. This method is mainly used for the determination of the low concentration suspensions.
Turbidimetry is the measurement of the transmitted light by the suspended particles to the incident beam. This is used for the determination of the high concentration suspensions.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Contact us if you are interested:
Email / Skype : kefaya1771@gmail.com
Threema: PXHY5PDH
New BATCH Ku !!! MUCH IN DEMAND FAST SALE EVERY BATCH HAPPY GOOD EFFECT BIG BATCH !
Contact me on Threema or skype to start big business!!
Hot-sale products:
NEW HOT EUTYLONE WHITE CRYSTAL!!
5cl-adba precursor (semi finished )
5cl-adba raw materials
ADBB precursor (semi finished )
ADBB raw materials
APVP powder
5fadb/4f-adb
Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
Payment terms: Western Union,MoneyGram,Bitcoin or USDT.
Deliver Time: Usually 7-15days
Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
263778731218 Abortion Clinic /Pills In Harare ,sisternakatoto
263778731218 Abortion Clinic /Pills In Harare ,ABORTION WOMEN’S CLINIC +27730423979 IN women clinic we believe that every woman should be able to make choices in her pregnancy. Our job is to provide compassionate care, safety,affordable and confidential services. That’s why we have won the trust from all generations of women all over the world. we use non surgical method(Abortion pills) to terminate…Dr.LISA +27730423979women Clinic is committed to providing the highest quality of obstetrical and gynecological care to women of all ages. Our dedicated staff aim to treat each patient and her health concerns with compassion and respect.Our dedicated group ABORTION WOMEN’S CLINIC +27730423979 IN women clinic we believe that every woman should be able to make choices in her pregnancy. Our job is to provide compassionate care, safety,affordable and confidential services. That’s why we have won the trust from all generations of women all over the world. we use non surgical method(Abortion pills) to terminate…Dr.LISA +27730423979women Clinic is committed to providing the highest quality of obstetrical and gynecological care to women of all ages. Our dedicated staff aim to treat each patient and her health concerns with compassion and respect.Our dedicated group of receptionists, nurses, and physicians have worked together as a teamof receptionists, nurses, and physicians have worked together as a team wwww.lisywomensclinic.co.za/
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Hemodialysis: Chapter 3, Dialysis Water Unit - Dr.Gawad
Snehal refractometry
1. Savitribai phule pune UNIVERSITY SEMINAAR ON
Miss. SNEHAL K. DHOBALE
M-PHARMACY – SEMESTER-1
YEAR 2014-15
Padm. Dr. D.Y.PATIL COLLEGE OF
PHARMACY,AKURDI, PUNE.
GUIDED BY,
PROF. M.T. MOHITE
2. CONTENT
Refractometry
Principle
Refractometer
Refractive index
Instrumentation
Factors affecting RI measurment
Calibration of Refractometer
Advances in Refractometry
Uses
2
3. REFRACTOMETRY
Refractometry is the method of measuring substances
refractive index (one of their fundamental physical
properties) for example, assess their composition or purity.
A refractometer is the instrument used to measure refractive
index ("RI"). Although refractometers are best known for
measuring liquids, for quick evaluation of concentration of
dissolved substances.
Measurement of refractive index of unknown substance.
measure substances dissolved in water and certain oils.
3
4. PRINCIPLE
Measurement of RI of unknown substance by measuring angle
of refraction made when the substance is brought into contact
with the medium (prism) of a known refractive index
4
5. REFRACTOMETER
A refractometer measures the extent to which light is bent (i.e.
refracted) when it moves from air into a sample and is typically
used to determine the refractive index (n) of a liquid sample.
The refractive index is a unitless number, between 1.3000 and
1.7000 for most compounds
The refractive index is a quantity which is a constant for a pure
substance under standard conditions of temperature and
pressure.
5
6. REFRACTIVE INDEX
The ratio of the speed of light in a vacuum to the speed of light
in another substance is defined as the refractive index for the
substance
The speed of light in a vacuum is always the same, but when
light moves through any other medium it travels more slowly
since it is constantly being absorbed and re-emitted by the
atoms in the material.
Samples with different refractive indexes will produce different
angles of refraction and this will be reflected in a change in the
position of the borderline between the light and dark regions.
6
7. REFRACTIVE INDEX (CONTI…)
Absolute index of refraction (N) is the relation of speed widening of light in the
vacuum to its speed in the present medium
Relative index of refraction (n) is the relation of speed widening of light in the
air to its speed in the present medium
In the case shown, the speed of
light in medium A is greater than
the speed of light in medium B.
The relationship between light's
speed in the two mediums (vA
and vB), the angles of incidence
( A) and refraction ( B) and the
refractive indexes of the two
mediums (nA and nB) is shown:
7
8. REFRACTIVE INDEX (conti…)
It is also commonly used to:
Help identify or confirm the identity of a sample by
comparing its refractive index to known values.
Assess the purity of a sample by comparing its refractive
index to the value for the pure substance.
Determine the concentration of a solute in a solution by
comparing the solution's refractive index to a standard curve.
8
9. INSTRUMENTATION
TYPES OF REFRACTOMETER
ABBE’sREFRACTOMETER
IMMERSION OR DIPPING
REFRACTOMETER
PULFRICH REFRACTOMETER
9
10. I.) ABBE REFRACTOMETER
Light refraction through liquids to determine
the amount of dissolved solids in liquids by
passing light through a sample and showing
the refracted angle on a scale.
RI of the prism should be greater than that of
the sample
In abbe refractometer, the RI can be read
directly, only a few drop of the liquid are
needed , and either white or monochromatic
light can be used.
This refractometer consist, mainly a telescope
and two matched right angle prisms.
10
11. I.) ABBE REFRACTOMETER (conti…)
The liquid is placed in contact with the prisms.
Many refractometers are equipped with a thermometer and a means of
circulating water through the refractometer to maintain a given
temperature.
Most of the refractive index measurements reported in the literature are
determined at 20 or 25 °C.
Operation consists of placing 1 or 2 drops of the water sample on the
prism, closing a glass plate over the sample, then looking through the
eyepiece for the reading
11
12. Analyzing Results Finding Refractive Indexes:
Comparison with the literature to know the identity of the
compound or to asses its purity
The following sources list refractive indexes for a wide variety of
substances:
12
The CRC Handbook of Chemistry and Physics
Lange's Handbook of Chemistry
The Merck Index
Chemical catalogs (e.g., the one from Aldrich
Chemical Co. ) MSDS datasheets
13. OPERATING THE BAUSCH & LOMB ABBE-3L REFRACTOMETER
Open the prism
assembly and
remove the tissue
Use a pipette to
apply your liquid
sample to the prism.
Be careful not to let
the glass pipet tip
touch the prism
Close the prism
assembly.
Turn on the lamp
using the switch on
the left side.
Adjust the lamp so
the light shines on
the prism .
13
14. AMICI PRISMS OR COMPENSATING
To prevent the chromatic
aberration
Light sources in abbe’s
refractometer :
i. natural light
ii. C - line of hydrogen
lamp(653.6nm)
iii. D - line of sodium vapor
lamp(589.3nm) –
iv. F - line of hydrogen
lamp(486.1nm)
v. G – line of mercury
vapor lamp(435.8nm)
PRISMS
14
15. Calibration of refractometer
1.
• Make sure that you are holding the refractometer horizontally, and open the daylight
plate to expose the main prism.
2.
• Using a plastic pipette, place two drops of distilled water on the prism.
3.
• Close the daylight plate and press it lightly so that the water spreads across the
entire surface of the prism without any air bubbles or dry spots. Allow the sample to
remain on the prism for 30 seconds.
4.
• Look through the eyepiece to see a circular field with graduations on either side. The upper
portion should be blue and the lower portion white. If the field is not in focus, twist the eyepiece
until the graduations are clearly distinguishable. The boundary between the blue and white
portions should fall on the zero mark of the graduations. If not, turn the calibration screw on top
of the refractometer until the boundary between the colors reaches the zero mark.
5.
• After calibrating the refractometer, open the daylight plate and pat dry the main
prism..
15
16. II.) IMMERSION REFRACTOMETER
The immersion or dipping refractometer is basically an Abbé
type refractometer of short range and without an illuminating
prism.
The dipping refractometer is used primarily for determining
solution concentrations, such as in the sugar industry,
pharmaceuticals, and milk. It is particularly useful for acids
since only the inert prism dips into the solution.
Immersion refractometers always work at the temperature of
the liquid, so they need built in temperature compensation
16
17. II.) IMMERSION REFRACTOMETER
Similar to abbes but lacks illuminating prism. lower surface of
the refracting prism dipped into the sample solution.
Simplest design is a refractometer that you just immerse
partially into solution to make a measurement.
In most cases dip refractometer is just a liquid proof Abbé
refractometer mounted in a tube, with an additional
immersible light source, or mirror that helps direct natural light
on the measuring prism surface.
17
18. II.) IMMERSION METHOD
The immersion method relies on having immersion oils of
known refractive index and comparing the unknown mineral to
the oil.
Immersion oil is available with refractive indices that cover the
range found for most minerals.
Typically the immersion oil will have indices of refraction in
the range 1.4 to 1.8 in increments of 0.002, 0.004 or 0.005.
There are two components to comparing the index of refraction
of the mineral and the immersion oil
I. Relief
II. Becke Line 18
19. 1.) Relief
Relief can be defined as the degree to which a mineral grain or
grains appear to stand out from the mounting material, whether it is
an immersion oil, Canada balsam or other medium, or another
mineral.
If the indices of refraction of the
oil and mineral are the same, light
passes through the oil-mineral
boundary un-refracted and the
mineral grains do not appear to
stand out.
If noil ≠ nmineral then the light
travelling though the oil-mineral
boundary is refracted and the
mineral grain appears to stand out.
19
20. 2.) BECKE LINE
Movement of the Becke line as the stage is lowered. The becke line may be
considered to consist of a cone of light that extends upwards from the
mineral grain.
If nmin < noil, the cone diverges upwards and if nmin > noil the cone
converges upwards.
If the stage is lowered, the plane of focus goes from F1 to F2 and the Becke
Line appears to move towards the material of the higher refractive index.
20
21. III.) PULFRICH REFRACTOMETER
Pulfrich refractometer is the design
(after Abbé refractometer) that
became commercially avilable in
19th century. It is another type
of critical angle refractometer
The Pulfrich refractometer is actually
only as accurate as a standard Abbé
(one unit in the fourth decimal place)
in absolute determinations.
However, it can give measurements to
2-3 units in the fifth-place for
differential measurements and for
dispersion determinations.
21
22. III.) PULFRICH REFRACTOMETER
Right angled prism attached
to a small glass block
containing the sample
light is incident at grazing
incidence(at right angle)
Angle of refraction is
measured with the help of
telescope n = RI of sample =
RI of glass block
n= RI OF SAMPLE
nG= RI OF GLASS BLOCK
22
24. Colloidal refractometry: meaning and measurement of refractive index
for dispersions. Mansur Mohammadi
Abstract
This paper introduces a new way of investigating the microstructure of high phase
volume dispersions.
It is a light scattering method where, instead of scattering intensities, one obtains
refractive index, n, of a dispersion The measured values of n on undiluted
dispersions can provide a measure of the volume-weighted average particle size.
The accurate measurement of n for turbid fluids is not trivial and total internal
reflection refractometers that rely on the visual identification of the degraded cut-off,
or critical, edge of a dark-light border (or even most of modern automatic ones)
cannot cope with this task.
Here a total internal reflection refractometer is described that relies
on differentiating the light profile for accurate identification of the degraded cut-off
edge.
It can cope with a wide range of concentrations and size distributions. The sizing
results for polystyrene latices and liposome dispersions compare well with
conventional methods.
24
25. Refractometry as a measure of the immunoglobulin status of the
newborn dairy calf: comparison with the zinc sulfate turbidity test
Naylor JM, Kronfeld DS. American Journal of Veterinary Research
Immunoglobulins were quantitated by single radial immunodiffusion in 34 female
Holstein-Friesian calves which had been kept with their dams for the first 24 hours
of life.
The mean immunoglobulin G1 (IgG1) concentration was 1.063 g/dl; IgG2, 0.093
g/dl; IgM, 0.171 g/dl; and IgA, 0.125 g/dl
Both serum total protein as measured by refractometer and zinc sulfate turbidity
measured at 498 nm gave good correlations with total protein, which were
significant, P less than 0.001.
Plasma total protein had a slightly poorer correlation with total immunoglobulins,
presumably due to variable fibrinogen content.
Plasma total protein gave a better correlation with total immunoglobulins than did
any of the immunoglobulin classes individually.
Total protein by refractometer underestimated naturally occurring or added
immunoglobulins by one-third 25
26. APPLICATIONS & USES
1) It is used in the examination of organic compounds (oils, solvents, etc.),
solutions, food products, serum protein concentration.
2) In veterinary medicine, a refractometer is used to measure the total
plasma protein in a blood sample and urine specific gravity.
3) In gemmology, a refractometer is used to help identify gem materials by
measuring their refractive index.
4) Since the index of refraction of a pure substance is constant at constant
temperature and pressure, it can be used as a means of identification.
5) It is used to determine the purity of oils, fats, and waxes.
6) It is used to determine the amount of sugar in sugar solutions and in
general, for determining total solids in fruit juices, tomato products,
honey, syrups and soda water
26
27. REFERENCES
1. Gurdeep.R. Chatwal, Sham k.Anand, INSTRUMENTAL METHOD OF
CHEMICAL ANALYSIS, Himalaya publishing house, 2008, p.no.2.382-2.597.
2. Skoog, Douglas A., F. James Holler and Timothy Nieman. PRINCIPLES OF
INSTRUMENTAL ANALYSIS. Fifth Edition. New York, 1998.p.no.156-178
3. http://www.refractometer.pl/hand-held-refractometer
4. www.refractometer.pl/
5. "Microscope Objectives: Immersion Media" by Mortimer Abramowitz and
Michael W. Davidson, Olympus Microscopy Resource Center (website), 2002
6. www.colorado.edu/physics/phys1230/phys1230.../6
7. Journal of dairy science, Evaluation of the Brix refractometer to estimate
immunoglobulin G concentration in bovine colostrum . J.D. Quigley1, A. Lago2
27