Lab - Vit A Det

Question 1

1 IU Vit A= ___ retinol

Answer 1

0.3 mcg

Question 2

Qualitative method of Vit A Det: retinol + esters react with these 2 acids to form a particular color

Answer 2

Trifluoroacetic acid
Trichloroacetic acid
Blue

Question 3

In quanti det of Vit A, the sample is first __ (process)

Then a (tool) is used

Answer 3

(Process):saponified

(Tool):HPLC

Question 4

[qualitative det]

The addition of ____(reagent) produces suspensjon of fluor in solvent

Answer 4

2-propanol

Question 5

[qualitative det]

The addition of ___ & __ (rgts) : improve separation

Answer 5

N-heptane

Saturated saline soln

Question 6

[qualitative det]

After centrifugation, layers are formed. Organic layer is color __

Answer 6

Yellow

Question 7

[qualitative det]

__ color indicates presence of Vit A

Answer 7

Blue

Question 8

[qualitative det]

Intensity of color indicates__

Answer 8

Conc of Vit A in sample

Question 9

[Qualitative det]

If blue/light blue color is observed, how must the findings be reported?

Answer 9

Positive and above 0.5mg/kg

Question 10

[quantitative det]

Enum components of HPLC

Answer 10

Operating pump
Injector
Reverse phase C18 column
Photometric detector
Data integrator

Question 11

[quanti det]

Standard to be used when running with samples with vit A conc below 1.5mg/kg

Answer 11

Low standard 2

Question 12

[quanti det]

Antioxidant added to each standard and sample flask

Answer 12

Pyrogallic acid

Question 13

[quanti det]

What does the glass bead do?

Answer 13

Promote even boiling

Question 14

[quanti det]

Role of glacial acetic acid soln

Answer 14

Neutralize KOH

Question 15

[quanti det]

The higher the ___ in the sample, the more precipitate will form

Answer 15

Fat content

Question 16

[quanti det]

Mobile phase + ratio : identify

Answer 16

Methanol:water
89:11

Question 17

[quanti det]

Flow rate : identify

Answer 17

1.3 mL/min

Question 18

[quanti det]

Wavelength : identify

Answer 18

323 nm

Question 19

[quanti det]

Retention time : identify

Answer 19

11-12 min

Question 20

[Quanti det]

Injection of standards must be repeated until ___

Answer 20

Peak heights/areas are reproducible

Question 21

[quanti det]

Intersperse with standard solution injections after every __ samples

Answer 21

9

Question 22

[quanti det]

What is mg(std) in formula for response factor for vit A?

Answer 22

mg (std)=mg of USP std wt in rgts

Question 23

[quanti det]

What is mL(std) in formula for response factor for vit A?

Answer 23

mL of std used in procedure

Question 24

[quanti det]

What is C(std) in formula for response factor for vit A?

Answer 24

Conc of USP Vit A as per certification

Question 25

[quanti det]

What is PH(std) in formula for response factor for vit A?

Answer 25

Peak height/area of standard fr chromatogram

Question 26

[quanti det]

What is 10,000 in formula for response factor for vit A?

Answer 26

Combined dilution factor for vit A std

Question 27

[quanti det]

What is PHsam in formula for vit A content?

Answer 27

Total sample peak height or area of all-trans

Question 28

[quanti det]

What is 100 in formula for vit A content?

Answer 28

Dilution volume of sample

Question 29

[quanti det]

What is W in formula for vit A content?

Answer 29

Weight of sample in g

Question 30

Vit A: a grp of fat soluble compounds that have bio activity of __

Answer 30

all-trans-retinol