The document discusses photometry and spectrophotometry, focusing on their principles, applications, and differences. Photometry measures the concentration of compounds in solutions by assessing light absorbance, while spectrophotometry measures how much light a substance absorbs at specific wavelengths. Both techniques have important roles in various industries and fields, including chemistry, biology, and environmental analysis.

1. BIO-CHEMISTRY
PHOTOMETRY AND SPECTOPHOTOMETRY.

2. TODAY WE GO THROUGH
What is the photometry?
Principle of photometry?
Uses of photometry?
What is spectrophotometry?
Principle of spectrophotometry?
Applications of spectrophotometry?
Difference between the photometry and spectrophotometry?

3. BEFORE GOING INTO THE TOPIC, LETS
LEARN FEW POINTS:
LIGHT: Light is electromagnetic radiation that shows
properties of both waves and particles. It exists in tiny energy
packets called photons.
FREQUENCY: It is the number of occurrences of a repeating
event per unit of time.
WAVE LENGTH: It is the distance between the two crest or
two troughs
WAVE: It is a kind of oscillation that travels through
space(peak) and matter(troughs).
SPEED OF LIGHT(C): 3×108ms.

4. PHOTOMETRY
Photometry is the technique that measures the
concentration of organic and inorganic compounds in a
solution by determining the absorbance of wavelengths of
light.
Photometry instruments have many laboratory and
practical applications.
It is the science of measurememt of light, in terms of its
perceived brightness to the human eye.

5. PRINCIPLE OF PHOTOMETRY
The basic principle of this technology involves
measurement of quantity of light absorbing analyte in a
solution.
This results in reflection of a light of lower intensity.
This can only applied to solution which follow the Beer
Lambert’s law.

6. WAVELENTHS
The wavelength of emitted light is specific for specific elements

7. USES OF PHOTOMETRY
Photometry is used in various industries like chemicals, soils,
agriculture, pharmaceuticals, in plants and water, and in
biological and microbiological laboratories.
It is used in determination of potassium, sodium, magnesium,
and calcium in biological fluids like serum, plasma, urine etc ,
is routinely carried out by photometer.
Analysis of industrial water natural water for determining
elements responsible for hard water is standard procedure in
many laboratories.

8. SPECTROPHOTOMETRY
It is a method to measure how much a chemical substance
absorb light y measuring the intensity of light as a beam of
light passes through sample solution.
These are widely used in various disciplines such as physics,
molecular biology, chemistry, and biochemistry.
The difference between the spectrometer and
spectrophotometer:
A spectrometer measures emission spectrum, as the light focused
on its entrance slit, dispersed and registered at different
wavelengths.
Spectrophotometer measures absorption spectrum of a sample
placed inside.

9. APPLICATIONS OF SPECTROPHOTOMETER
Qualitative analysis: used to identify classes of compound in
both pure state and in biological preparations.
Determination of double standard DNA: DNA absorbed at
260 nm. This absorbance increase with rise in temperature, as
double standard DNA become single standard.
Molecular weight determination: the molecular weight of
amines, sugars, and many aldehyde and ketone compounds can
be determined.

11. DIFFERENCE BTW PHOTOMETRY AND
SPECTROPHOTOMETRY
Photometry measures the total brightness as seen
by the human eye.
Spectrophotometry measures the intensity at each
wavelength on the whole range of electromagnetic
spectrum for which the measurement are
necessary.