Lecture 16 Mass Spec, Osmometry, and POC Testing

Question 1

For mass spectrometry, on what basis are samples ionized and then separated?

Answer 1

Based on their mass-to-charge ratio (m/z)

Question 2

Define vaporization

Answer 2

Sample is energized to the state of gas

Question 3

Define Ionization

Answer 3

Gas is bombarded with high-speed electrons, making positively charged ions

Question 4

Define acceleration

Answer 4

An electric field accelerates the positively charged ions

Question 5

Define deflection

Answer 5

A strong magnetic field deflects the particles based on their mass-to-charge (m/z) ratio

Question 6

Define detection

Answer 6

A detector counts the numbers of each of the ions upon impact

Question 7

Define osmometry

Answer 7

Measures the concentration of solute particles that contribute to osmotic pressure of a solution (i.e., electrolytes, proteins, etc.)

Question 8

Define osmole

Answer 8

A unit of measurement that describes the number of moles of a compound that contribute to the osmotic pressure of a chemical solution.

Question 9

Define total osmotic pressure

Answer 9

Minimum pressure that must be applied to a solution to halt the flow of solvent molecules through a semipermeable membrane (movement exerts osmotic pressure).

Question 10

Osmotic pressure governs the movement of ___ across a membrane that separates two solutions.

Answer 10

solvent

Question 11

Define osmolality

Answer 11

The number of osmoles of solute per kilogram of solvent (w/w)

Question 12

Osmolality expresses concentrations relative to what?

Answer 12

The mass of the solvent

Question 13

(T/F) Osmolality is temperature dependent.

Answer 13

FALSE, osmolality is temperature independent.

Question 14

What instrument is used to measure osmolality?

Answer 14

An Osmometer

Question 15

Define freezing point depression

Answer 15

It measures the freezing point of a solution (colligative property)

Question 16

How is the freezing point of a solute effected if the freezing point decreased.

Answer 16

Increase solutes in a solution as freezing point decreases.

Question 17

What does freezing point depression measure?

Answer 17

The total solute concentration (not affected by solute size)

Question 18

Which method provides a more exact measurement of solute concentration: freezing point depression or specific gravity?

Answer 18

Freezing point depression

Question 19

Define osmolarity

Answer 19

The number of osmoles per liter of solution (w/v). Expresses concentration per volume of solvent.

Question 20

Define point of care testing (POCT)

Answer 20

Testing performed at or near the site of patient care