Lecture 13 Lab Lingo

Question 1

Absorbance Spectrophotometry

Answer 1

Concentration of an unknown sample is determined by measuring its absorption of light at a particular wavelength and comparing the rest with that of a known standard solution measured at the same time, and with the same wavelength.

Question 2

Absorbed

Answer 2

Taken in or soaked up.

Question 3

Beer’s Law

Answer 3

The amount of light absorbed by a solution is directly proportional to the concentration of a solution (↑ concentration ↑ light absorbed)

Question 4

Bioluminescence

Answer 4

Form of chemiluminescence found in biological system

Question 5

Blank Solution (Blank)

Answer 5

Contains all of the reagents used in the procedure w/o the unknown substance

Question 6

Chemiluminescence

Answer 6

Chemical Reaction that produces light without producing heat

Question 7

Concentration

Answer 7

A measure of the amount of solute that has been dissolved in a given amount of solvent or solution.

Question 8

Cuvette

Answer 8

Small vessel designed to hold a liquid sample in the light path of a spectrophotometer for measurement

Question 9

Directly Proportional

Answer 9

Related so that one becomes larger or smaller when the other becomes larger or smaller.

Question 10

Electrochemiluminescence

Answer 10

The process where species generated at electrodes undergo electron-transfer reactions to form excited states that emit light

Question 11

Electromagnetic Radiation

Answer 11

A kind of radiation including visible light, radio waves, gamma rays, and X-rays, in which electric and magnetic fields vary simultaneously.

Question 12

Fiberoptics

Answer 12

Used to improve directional control of the light beam within the instrument

Question 13

Fluorescence

Answer 13

When a molecule absorbs light at one wavelength and reemits light at a longer wavelength

Question 14

Fluorescence Spectrophotometry

Answer 14

Uses a beam of light, typically UV light, to excite electrons in molecules causing them to emit light of a different wavelength.

Question 15

Fluorimetry

Answer 15

Measures the fluorescence at a specific emission wavelength after induction with a light pulse of a specific excitation wavelength.

Question 16

Fluorometer

Answer 16

Measures fluorescent intensity. Mainly the same components as spectrophotometer with the exception of the light source, sample cell, and detector.

Question 17

Fluorophore

Answer 17

An atom or molecule that fluoresces.

Frequently used as tags/labels in immunoassay and flow cytometry.

Question 18

Frequency

Answer 18

Measured in hertz (Hz) which is equal to one event per second.

Question 19

Inversely Proportional

Answer 19

When the value of one quantity increases with respect to decrease in other or vice-versa.

Question 20

Light

Answer 20

Form of electromagnetic radiant energy that travels in waves.

Question 21

Light Source

Answer 21

Incandescent lamps, hydrogen or deuterium lamps, lasers, etc.

Question 22

Linearity

Answer 22

The property of a mathematical relationship that can be graphically represented as a straight line. Linearity is closely related to proportionality.

Question 23

Luminometer

Answer 23

Measures light emission via chemiluminescence, bioluminescence, and electrochemiluminescence.

Question 24

Monochromator

Answer 24

Isolates radiant energy of a desired wavelength(s) while excluding other unwanted wavelengths.

Question 25

Nanometers

Answer 25

A nanometer is one billionth of a meter, or 10^-9 meters.

Question 26

Nephelometry

Answer 26

Based on detection of the portion of light scattered by the particles in a solution toward a detector not in the direct path of the transmitted light.

Used to assay large particles at low concentrations.

Question 27

Photodetector

Answer 27

Convert light into a measurable electrical signal by detecting photons that strike a photosensitive or photoemissive surface.

Question 28

Photometry

Answer 28

Technique used to determine the concentration of a substance by measuring variation in its color intensity.

Question 29

Plank’s Equation

Answer 29

Shows relationship between wavelength and energy.

Question 30

Readout Device

Answer 30

Information from an automatic device (as a computer) that is recorded or presented in a form that can be seen.

Question 31

Reflectance Density

Answer 31

The amount of light absorbed by the colored reaction product on the smooth surface.

Inversely proportional to the light intensity reflected by the sample.

Question 32

Reflectance Spectrophotometry

Answer 32

Light reflected from the surface of a colorimetric reaction is used to measure the amount of unknown colored product (quantitative)

Question 33

Spectrophotometry

Answer 33

The measurement of light at selected wavelengths, typically in ranges of ultraviolet (UV), visible, and infrared light.

Question 34

Spectrum of Energy

Answer 34

Short wavelengths gamma rays; long wavelengths radio frequencies.

Visible: ~380 - 750 nm
UV: 10 - 400 nm

Color of light seen by the naked eye is transmitted (or reflected), all other wavelengths are absorbed.

Question 35

Standard Curve

Answer 35

Absorbance (or %T) of known standards is obtained.

Absorbance and concentrations are plotted on linear graph paper; concentrations of unknowns can be obtained using the curve produced based on the absorbance measured.

Question 36

Transmitted

Answer 36

Light being reflected off of a surface/sample; the color that we see.

Question 37

Turbidimetry

Answer 37

Measures the reduction of light transmitted through a homogeneous solution due to light’s scattering (solution becomes turbid)

Used to assay small particles at high concentrations.

Question 38

Visible Light

Answer 38

Wavelengths of light between 380 and 750 nm.

Red

Question 39

Wavelength

Answer 39

The distance between two peaks as light travels in a wavelike manner.