Spectrophotometer

Question 1

Spectrophotometry or Colorimetry It is a technique that is used to

Answer 1

determine the concentration of a colored solution by the application of the Beer—Lambert law

Question 2

Beer—Lambert law

Answer 2

The concentration of a solute is directly proportional to the absorbance (Light absorbed) (optical density) and inversely proportional to the transmittance

Question 3

A + T =

Answer 3

1

Question 4

Spectrophotometer or Colorimeter

Answer 4

It Is a device used to measure the Intensity of light (شدة الضوء) after it has passed through an absorbing medium (sample)

Question 5

Spectrophotometer or Colorimeter Consists of

Answer 5

Sample Compartment – Mode - Zero control (0 A and 0 T)

Readout (display) - Wavelength selection - print

Question 6

Mechanism of Spectrophotometer action

Answer 6

1. Light source (Infrared / UV / Visible) sent light to the Condenser lens
2. Lens collect it on Prism which reflect color into 7 spectral colors
3. By wavelength selector the specific color goes from slit which select transmits the desired wavelength and absorbs all other wavelength and direct light to the sample solution (in cuvette)
4. Photoelectric result will appear by photocell
5. Display result in digital display

Question 7

The sample unknown solution is compared with a

Answer 7

known standard to obtain the exact concentration of the unknown sample

Question 8

Sample Conc.

Answer 8

(A Sample)/(A Standard ) X Standard Conc.

Question 9

If the substance by itself is colorless, it can ..

Answer 9

chemically converted to a colored substance

Question 10

Before using the Spectrophotometer device

Answer 10

The zero point of the Colorimeter should be first adjusted with a solution known the blank

Question 11

The types of blanks

Answer 11

Water , Air or Reagent blank this depends upon the procedure used (Kits)

Question 12

Steps in spectrophotometer

Answer 12

1. Adjust wavelength
2. Zero control by placing blank
3. Remove the blank
4. Place the slandered
5. Place the sample
6. Take the reading

Question 13

Photocell function

Answer 13

• Measures the intensity of the light transmitted through the solution after absorption
• It converts the radiation to electrical energy

Question 14

The spectrophotometer needs … Tubes

Answer 14

3

Blank – Sample – Slandered

Question 15

R1

Answer 15

Standard known conc.

Present in Standard tube only

Question 16

R2

Answer 16

Coloring reagent

Present in 3 tubes

Question 17

Blood analysis may be carried out on

Answer 17

whole blood, plasma or serum depending on the distribution of the substance which is being studied

Question 18

Blood collected in

Answer 18

1. Wasserman tube (Blue cap)
2. Vacutainer (no anticoagulant) – (Red cap)

Question 19

Lab equipment

Answer 19

1. Tourniquet
2. Alcohol Swab
3. Syringe (With beveled end up to direct blood to Syringe)

Question 20

Whole blood

Answer 20

Diluted by water to hemolysis RBCs

Detect : Hb , lactate, pyruvate and ammonia

Question 21

Plasma Detect

Answer 21

Clotting factors as fibrinogen , prothrombin

Question 22

Serum Detect

Answer 22

Glucose Cholesterol , albumin and enzymes

Question 23

Collecting Plasma or serum by using

Answer 23

Micropipette

Question 24

What is deference between plasma and serum

Answer 24

Plasma : Centrifuge uncoagulated blood / presence of fibrinogen

Serum : Centrifuge coagulated blood

Question 25

Centrifuge blood ... to have serum or plasma

Answer 25

15 RPM to 10 Min

Question 26

Na or K citrate Mechanism

Answer 26

Inhibits blood coagulation by combining with Ca

Question 27

Na or K citrate Cap Color

Answer 27

Black → ESR Light Blue → Prothrombin time

Question 28

Na Fluoride Mechanism

Answer 28

Inhibits enolase enzyme so stops the consumption of glucose

Question 29

Na Fluoride detect

Answer 29

Glucose

Question 30

Na Fluoride Cap Color

Answer 30

Gray

Question 31

EDTA Mechanism

Answer 31

Inhibits blood coagulation by chelation of Ca and Mg

Question 32

EDTA detect

Answer 32

CBC and blood film

Question 33

EDTA Cap Color

Answer 33

Violet

Question 34

EDTA Note

Answer 34

Not used in measuring ALP enzyme (no Mg) and Ca and Mg)

Question 35

Heparin Mechanism

Answer 35

Anti-thrombin

Question 36

Heparin detect

Answer 36

Blood gases (O2 – CO2)

Question 37

Heparin Cap color

Answer 37

Green

Question 38

Heparin note

Answer 38

Not used in blood film (black film - aggregation of cells) and PCR

Question 39

K oxalate

Answer 39

Not used anymore (aggregation of cells)