M4-7 Flashcards
(89 cards)
1
Q
used to measure various optical property of a material
A
POLARIMETRY
2
Q
- is the measurement and interpretation of the polarization of transverse waves most notably electromagnetic waves such as radio or light waves
A
POLARIMETRY
3
Q
POLARIMETRY
it is done on electromagnetic waves that have traveled through or have been ____, ____, or ____ by some material in order to characterize that object
A
reflected, refracted, or diffracted
4
Q
POLARIMETRY
Polarimetry of THIN FILMS and SURFACES is commonly known as
A
ellipsometry
5
Q
POLARIMETRY
a scientific instrument used to measure the ANGLE OF ROTATION caused by passing polarized light through an optically active substance
A
POLARIMETER
6
Q
POLARIMETRY
Polarimeters are used in the ____ for determining quality of both juice from sugar cane and the refined sucrose
A
sugar industry
7
Q
POLARIMETRY
Often, the sugar refineries use a MODIFIED polarimeter with a flow cell called a ____
A
SACCHARIMETER
8
Q
POLARIMETRY
the Polarimeter is made up of two ____
A
NICOL PRISMS
(polarizer & analyzer)
9
Q
POLARIMETRY | POLARIMETER
NICOL PRISMS:
fixed
A
polarizer
10
Q
POLARIMETRY | POLARIMETER
NICOL PRISMS:
can be rotated
A
analyzer
11
Q
POLARIMETRY | POLARIMETER | PARTS
- light source
- filter out ALL but specific wavelength of light
A
MONOCHROMATOR
12
Q
POLARIMETRY | POLARIMETER | PARTS
convert light beam to a polarized light
A
fixed polarizer
13
Q
POLARIMETRY | POLARIMETER | PARTS
where samples are put
A
sample tube
14
Q
POLARIMETRY | POLARIMETER | PARTS
used to determine degree of rotation
A
movable polarizer
15
Q
REFRACTIVE INDEX
for HIGH PRECISION measurement of an index of refraction (up to 4 DP)
A
ABBE REFRACTOMETER
16
Q
REFRACTIVE INDEX
the index of refraction is represented into how many decimal points
A
4 DP
17
Q
a measure of the bending of a ray of light when passing from one medium into another
A
INDEX OF REFRACTION or REFRACTIVE INDEX
18
Q
used to confirm identity of a substance (volatile oils)
A
INDEX OF REFRACTION or REFRACTIVE INDEX
19
Q
REFRACTIVE INDEX
used to measure DISSOLVED SUGAR
A
BRIX SCALE
20
Q
REFRACTIVE INDEX
1 degree of Brix is equal to
A
1g of sucrose per 100g of solution
21
Q
REFRACTIVE INDEX
PROCEDURE USING THE ABBE REFRACTOMETER
A
- plug in
- switch on
- open the prism assembly
- apply 3-4 drops of the sample
- close the prism assembly
- look in the eyepiece
- adjust to borderline
- read the scale
- open the prism assembly
- clean
- close the prism assembly
- switch off
22
Q
REFRACTIVE INDEX | ABBE REFRACTOMETER
what type of dropper should be used in applying the liquid sample
A
plastic dropper
glass dropper should not be used to avoid scratching the glass
23
Q
A
24
Q
REFRACTIVE INDEX | ABBE REFRACTOMETER
the borderline between the light and dark region is placed exactly at the ____
A
center of crosshair
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# **REFRACTIVE INDEX | ABBE REFRACTOMETER**
how to **clean** the refractometer
1. dabbing the sample with cotton
2. washing the prism with cotton moisteneed w/ ethanol
26
an electronic instrument measuring the **pH acidity** or **alkalinity** of a liquid
pH METER
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# **pH**
a typical pH meter consists of:
| (2)
1. glass electrode
2. electronic meter
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# **pH**
A TYPICAL pH METER CONSISTS OF:
* a **special measuring probe**
glass electrode
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# **pH**
A TYPICAL pH METER CONSISTS OF:
* measures and **displays** the **pH reading**
ELECTRONIC METER
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# **pH**
PROCEDURE OF USING THE pH METER
1. switch on
2. calibrate
3. rinse w/ distilled water, dab w/soft tissue
4. immerse in the sample for 1-2mins
5. wait until the reading
6. remove from the sample
7. rinse w/ distilled water, dab w/ soft tissue
8. perform two trials
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# **pH**
how many **trials** should be performed
two
32
# **pH**
how **long** should the electrode be **immersed** in the sample
1-2 mins
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this should be treated with **extreme care** because it is **very fragile** and **expensive**
electrode
34
# **pH**
measures pH as the activity of **hydrogen cations**, surrounding a **thin-walled glass bulb** at its tip. it produces a **small voltage** (about 0.06 volt per pH unit) that is measured and displayed as pH units by the meter
pH probe (electrode)
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# **pH**
the **pH probe** measures pH as the activity of ____
hydrogen cations
36
# **pH**
the **pH probe** measures the pH activity of **hydrogen cations**, surrounding a ____ at its tip
thin-walled glass bulb
37
# **pH**
the **pH probe** produces a ____
small voltage -- 0.06 volt per pH unit
38
# **pH**
**voltage** the the **pH probe** produces
0.06 volt per pH unit
39
# **pH | PROBE (ELECTRODE)**
**GLASS** electrode is typically **stored** and **immersed** in ____
acidic solution
pH 3.0
40
# **pH | PROBE (ELECTRODE)**
in an **emergency**, ____ can be used
acidified tap water
41
# **pH | PROBE (ELECTRODE)**
must **NEVER** be used for **longer-term** probe **storage**
distilled or deionized water
42
# **pH | PROBE (ELECTRODE)**
why are **distilled** or **deionized water** must NEVER be used for longer-term probe storage
the ionless water sucks ions out of the probe membrane whihc degrades it
43
# **pH | PROBE (ELECTRODE)**
COMBINED ELECTRODES
glass membrane + reference electrode
44
# **pH | PROBE (ELECTRODE)**
**COMBINED** electrode are **better stored** and **immersed** int he ____ to **avoid diffusion** of the **electrolyte (KCl)** out of the liquid junction
bridge electrolyte (3M KCl)
45
# **pH**
for **more precise** measurements, a three ____ calibration is preferred
buffer solution
46
# **pH**
three **buffer** solution
pH 7, pH 4, pH 10
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# **pH | BUFFER SOLUTION**
* **pH 7** is essentially, a ____ calibration
* **first** calibration
zero point calibration
48
# **pH**
how to **calibrate**
calibrate to pH 7 first, then calibrate again to the pH closest to the popint of interest
49
# **pH**
the **probe** is rinsed with ____ or ____ to **remove** any **traces** of the solution being measured
distilled water or deionized water
50
# **pH**
OTHER METHODS OF pH DETERMINATION
1. pH indicators
2. pH strips
3. potentiometric method
51
# **MOISTURE (WATER) CONTENT**
many drugs official in the USP/NF contain **varying quantities of water** either is ____ or as ____
water of crystallization (hydrates)
water in the absorbed form
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this is necessary to ensure the **uniformity** in the official drug
MOISTURE (WATER) CONTENT
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# **MOISTURE (WATER) CONTENT**
**control of amount of water** contained in chemicals is important in ____ and in **determination** of the **dosage** of substances such as medicaments
making solutions of definite concentration
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# **MOISTURE (WATER) CONTENT**
offers **RELIABILITY** and **SIMPLICITY** to measure **moisture** or **solids content** in samples ranging from **powders** to **liquids**
IR-35 MOISTURE ANALYZER
55
# **MOISTURE (WATER) CONTENT**
PROCEDURE ON IR-35 MOISTURE ANALYZER
1. switch on
2. set drying parameters (may skip)
3. open sample chamber, place unused sample pan
4. tare the sample pan
5. distribute about **2 grams** of sample **evenly** on the pan
6. close the sample chamber (record the weight before drying) - drying stops after **10 mins** (record the weight after drying)
7. open the sample chamber, remove the pan
8. remove sample
9. switch off
56
# **MOISTURE (WATER) CONTENT**
USP CRITERIA:
**STARCH** USP: **Cornstarch** & **Wheat starch**
NMT 15%
57
# **MOISTURE (WATER) CONTENT**
USP CRITERIA:
**STARCH** USP: **Tapioca** starch
NMT 18%
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# **MOISTURE (WATER) CONTENT**
USP CRITERIA:
**STARCH** USP: **Potato** starch
NMT 21%
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# **MOISTURE (WATER) CONTENT**
**ACACIA** USP
NMT 15%
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# **MOISTURE (WATER) CONTENT**
**LACTOSE** USP
NMT 0.5%
61
# **MOISTURE (WATER) CONTENT**
**TALC** USP
NMT 6.5%
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# **MOISTURE (WATER) CONTENT**
**METHYLCELLULOSE**
NMT 5%
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# **MOISTURE (WATER) CONTENT**
**REFINED WHITE SUGAR**
0.25% - 1.0%
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# **MOISTURE (WATER) CONTENT**
FORMULA
wt **before** drying - wt **after** drying / wt before drying x 100
65
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
based upon the quantitative reaction of water with an **anhydrous solution** of **SULFUR DIOXIDE** and **IODINE** in the presence of a buffer
METHOD IA:
Karl Fischer **Direct** Titration
66
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
FORMULA:
Karl Fischer **Direct** Titration
%water content = S x F / mg x 100
| S = volume of reagent used
F = water equivalence factor
67
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
**EXCESS** KF reagent is added to the sample, and the **unreacted** reagent is **titrated** with a **standard solution of water** in a solvent such as **methanol**
METHOD IB:
KARL FISCHER **RESIDUAL** TITRATION
68
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
a **MICRO**-method
METHOD IC:
KARL FISCHER **COULOMETRIC** TITRATION
69
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
* for **VEGETABLE** drugs containing **2%** or **more** moisture
METHOD II:
AZEOTROPIC / TOLUENE DISTILLATION
70
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
DISADVANTAGE of **Azeotropic / Toluene distillation**
requires LARGE amount of sample
50 - 100g
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# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
determines the amount of **VOLATILE MATTER** of any kind that is driven off under the conditions specified
METHOD III:
GRAVIMETRY (LOSS ON DRYING)
72
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
THERMOGRAVIMETRIC methods
1. Oven drying
2. Infrared drying
3. Halogen drying
4. Microwave drying
73
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
CHEMICAL method
1. Calcium carbide method
2. Distillation (Azeotropic: Toluene & Xylene)
3. Karl Fischer titration
74
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
SPECTROSCOPIC method
1. Infrared spectroscopy
2. Microwave spectroscopy
3. NMR spectroscopy
75
# **MOISTURE (WATER) CONTENT | OFFICIAL METHODS**
SPECTROSCOPIC:
* the **MOST SUCCESSFUL** of water content determination in **FOODS**
* **rapid**, **accurate**, **non destructive** to the sample
NMR SPECTROSCOPY
76
# **MOISTURE (WATER) CONTENT | SIGNIFICANCE**
monitoring of ____ **prior** to **compression** and **encapsulation** procedures
tablet granulations
77
# **MOISTURE (WATER) CONTENT | SIGNIFICANCE**
water / moisture content of certain drugs such as ____ should be kept between the range of **0.5%** to **0.1%** to **prevent bacterial growth** that helps **enhance product stability**
antibiotic suspension
78
# **MOISTURE (WATER) CONTENT | SIGNIFICANCE**
the water/moisture content of **antibiotic drugs for suspension** should be kept between the range of ____ to **prevent bacterial growth** which will help **enhance product stability**
0.5% - 1.0%
79
# **POLARIMETRY**
**circular birefringence** is also known as
optical rotation
or
optidal rotary dispersion
80
# **POLARIMETRY**
the prisms may be **compared** to as **slits** ____ and ____
S1 S2
81
# **POLARIMETRY**
PRIMSM:
allows ONLY those light waves which move in a **SINGLE PLANE**
S1
82
# **POLARIMETRY**
SOLVENTS:
**optically INactive chemicals**
distilled water
ethanol
methanol
83
the angle through whihc the **plane of polarization** is **rotated** when **polarized** light passes htrough a layr of liquid
optical rotation
84
# **OPTICAL ROTATION**
expressed in
angular degrees
## Footnote
`
85
# **OPTICAL ROTATION**
in the **SI**, the angle of optical rotation is expressed in
radians
86
# **OPTICAL ROTATION**
the measurement of optical rotation should be carried out at the what **temperature**
20-25C
87
# **MOISTURE CONTENT**
LIMITATION:
do **NOT** distinguish weight loss due to **vaporization** of **water** from other **volatile comounds**
THERMOGRAVIMETRIC
88
# **MOISTURE CONTENT**
APPLICATION:
systems with MC of **more than 0.1%**
thermogravi
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