Lab - Vit A Det Flashcards Preview

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Flashcards in Lab - Vit A Det Deck (30)
1

1 IU Vit A= ___ retinol

0.3 mcg

2

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

Trifluoroacetic acid
Trichloroacetic acid
Blue

3

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

Then a (tool) is used

(Process):saponified
(Tool):HPLC

4

[qualitative det]
The addition of ____(reagent) produces suspensjon of fluor in solvent

2-propanol

5

[qualitative det]
The addition of ___ & __ (rgts) : improve separation

N-heptane
Saturated saline soln

6

[qualitative det]
After centrifugation, layers are formed. Organic layer is color __

Yellow

7

[qualitative det]
__ color indicates presence of Vit A

Blue

8

[qualitative det]
Intensity of color indicates__

Conc of Vit A in sample

9

[Qualitative det]
If blue/light blue color is observed, how must the findings be reported?

Positive and above 0.5mg/kg

10

[quantitative det]
Enum components of HPLC

Operating pump
Injector
Reverse phase C18 column
Photometric detector
Data integrator

11

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

Low standard 2

12

[quanti det]
Antioxidant added to each standard and sample flask

Pyrogallic acid

13

[quanti det]
What does the glass bead do?

Promote even boiling

14

[quanti det]

Role of glacial acetic acid soln

Neutralize KOH

15

[quanti det]
The higher the ___ in the sample, the more precipitate will form

Fat content

16

[quanti det]
Mobile phase + ratio : identify

Methanol:water
89:11

17

[quanti det]
Flow rate : identify

1.3 mL/min

18

[quanti det]
Wavelength : identify

323 nm

19

[quanti det]
Retention time : identify

11-12 min

20

[Quanti det]
Injection of standards must be repeated until ___

Peak heights/areas are reproducible

21

[quanti det]
Intersperse with standard solution injections after every __ samples

9

22

[quanti det]
What is mg(std) in formula for response factor for vit A?

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

23

[quanti det]
What is mL(std) in formula for response factor for vit A?

mL of std used in procedure

24

[quanti det]
What is C(std) in formula for response factor for vit A?

Conc of USP Vit A as per certification

25

[quanti det]
What is PH(std) in formula for response factor for vit A?

Peak height/area of standard fr chromatogram

26

[quanti det]
What is 10,000 in formula for response factor for vit A?

Combined dilution factor for vit A std

27

[quanti det]
What is PHsam in formula for vit A content?

Total sample peak height or area of all-trans

28

[quanti det]
What is 100 in formula for vit A content?

Dilution volume of sample

29

[quanti det]
What is W in formula for vit A content?

Weight of sample in g

30

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

all-trans-retinol