Turbidimetry + Nephelometry + Spectrometry

Question 1

What is turbidimetry?

Answer 1

Turbidimetry is the process of measuring the loss of intensity of transmitted light due to the scattering effect of particles suspended in a solution.

Question 2

How is turbidimetry done?

Answer 2

Light is passed through a filter creating a light of known wavelength which is then passed through a curvette containing a solution.

Question 3

What is turbidimetry used for?

Answer 3

Turbidimetry can be used to determine the concentration of proteins in biological fluids, such as urine and blood, or to estimate the number of cells present in a solution.

Question 4

What does turbidimetry measure?

Answer 4

Turbidimetry measures the amount of light transmitted as it hits particles in a solution.

Question 5

is turbidimetry measured at an angle

Answer 5

no

Question 6

What does nephelometry measure?

Answer 6

Nephelometry measures the amount of light scattered as it hits particles suspended in
a solution

Question 7

What is nephelometry used for?

Answer 7

Nephelometry is used to measure the concentration of antibodies. such as
immunoglobulins, in blood. It is used to diagnose different types of cancer, arthritis,
and liver disease.

Question 8

What is nephelometry?

Answer 8

Nephelometry is the detection of light energy scattered or reflected toward a detector that is not in the direct path of the transmitted light. It is a technique which is commonly used in clinical laboratories. It is based on the principle that a dilute suspension of small particles will scatter light which is passed through it.

Question 9

How is nephelometry done?

Answer 9

Nephelometry is based on the principle that a dilute suspension of small particles will scatter light (usually a laser) which passes through it (rather than absorbing it). The amount of scatter is determined by collecting the light at an angle (usually 30 or 90 degrees).

Question 10

The amount of scatter is determined by

Answer 10

Collecting the light at an angle (in neph) (usually 30 or 90 degrees)

Question 11

What angle is the light collected at in nephelometry?

Answer 11

30 or 90 degrees

Question 12

What is spectrophotometry?

Answer 12

Spectrophotometry is a method of measuring the amount of light absorbed or transmitted by a chemical substance or how many chemicals are in a solution by measuring the intensity of light that is not absorbed by passing it through a sample.

There are two types of spectrophotometry depending on the wavelength of light utilised:

· A UV-visible spectrophotometer (which uses light over the ultraviolet and visible range (185-700 nm))

· An IR spectrophotometer (which uses light over the infrared range (700-1500 nm))

Question 13

What can spectrometry be used for?

Answer 13

Spectrophotometry can be used to diagnose infections because it provides information on the state of cell metabolism. This is because as the disease progresses, cell metabolism changes.

Another way it can be used to diagnose infections is because it can be used to determine the concentration of infection in bone fluid.

In clinical applications, spectrophotometry can be used to examine blood or spinal fluid for clinical diagnosis.

Question 14

What are the limitations of spectrophotometry?

Answer 14

· Absorbance depends on the wavelength of light used so some substances may absorb more light than others.

· If an incorrect cuvette size is used, results may be inaccurate.

· Low sensitivity so results won’t be as precise, therefore they won’t be as accurate as other tests.

Question 15

What is the method of spectrometry?

Answer 15

1. Spectrophotometry is measured using a spectrophotometer which consists of two instruments, a spectrometer and photometer.
2. A spectrometer produces the light of the wavelength, and a photometer measures the amount of light that passes through a sample to measure the intensity of light.
3. A spectrophotometer also contains a light source, cuvette, monochromator, digital display, detector of transmitted light, and data analysis software.
4. The sample is first placed into the sample chamber where it will be analysed.
5. A lamp provides a source of light
6. The beam of the light strikes the diffraction grating which works like a prism and separates the light into its component wavelengths (individual colours)
7. A slit is then passed through the component wavelengths and the prism is then rotated so that only one specific wavelength reaches the exit slit.
8. Light interacts with sample
9. Detector of transmitted light measures the absorbance and transmittance of light of the sample
10. Spectrophotometer completes calculations and an analysis of data.
11. The results of the test are then displayed on the digital display.

Question 16

What are the advantages of spectrometry?

Answer 16

Versatility, low cost, easy implementation, accurate, easy, quick and cheap method of analysis, etc.

Question 17

How many types of spectrophotometers are there?

Answer 17

2

Question 18

What’s the difference between light absorbance and transmittance?

Answer 18

absorbance is light turned into energy, transmittance is the movement of electromagnetic waves

Question 19

meaning of wavelength?

Answer 19

the distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave

Question 20

what does nm stand for in spectrophotometry?

Answer 20

nanometre

Question 21

what visible light range does an UV-visible spectrophotometer have?

Answer 21

185-700nm

Question 22

what visible light range does an IR spectrophotometer have?

Answer 22

700-1500nm

Question 23

what is the electromagnetic spectrum?

Answer 23

the range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies.