Travels as electromagnetic wave

the proportion of wavelength and electromagnetic energy is _

LAW OF COLORIMETRY the concentration of a solution for the known path length is directly proportional to its absorption of light.

TYPES OF ELECTROMAGNETIC ENERGIES

Types of Cuvette for solutions that do not etch glass

distance between two peaks as the light travels in a wavelike manne

Types of Cuvette does not absorb UV radiation at wavelength below 320 nm

Types of Cuvette good for 340 nm and above (visible region)

Visible-spectra Wavelength

An Internal Component of Spectro which measure light intensity by converting light signal into electrical signal

Non-visible spectra below 340nm

Non visible spectra that above 700nm

Type of detector composed of a film of light sensitive material (e.g. Selenium) on an iron plate with a transparent layer of silver

Type of detector that when light passing through the semi-conductive metal layer falls upon the Selenium surface, electrons are released in proportion to the intensity of light and are collected to the silver layer to produce a negative charge

Wavelength is expressed in

Type of detector that has as photosensitive material that gives off electrons when light energy strikes it

Measurement of the wavelength and the intensity of electromagnetic radiation in the visible region of the spectrum.

Used for identification and determination of concentrations of substances that absorb light

Kinds of Colorimetry

Kind of Colorimetry Relies on visual acuity to determine end-point

Kind of Colorimetry primary analytical utility of spectrophotometry or filter photometry is the isolation of discreet portion of spectrum for the purposes of measurement

Kinds of Photoelectric Colorimetry

Photoelectric Colorimetry where it make use of prisms and/or diffraction gratings as monochromator to disperse the radiant energy into a continuous spectrum

Photoelectric Colorimetry where it make useof filters (interference or transmission) to isolate part of the spectrum

LAW OF COLORIMETRY The concentration of the solution is directly proportional to the amount of light absorbed and inversely proportional to the logarithm of transmitted light

LAW OF COLORIMETRY Absorbance is directly proportional to the length of light path

An Internal Component of Spectro that provides a continuous spectrum of white light which can be separated at different wavelengths

Most commonly used light source produces energy wavelength from 340 – 700 nm (visible region); used for moderately diluted solution

A light Source which Iodine used to prevent the decomposition on the vaporized tungsten from the hot filament of light

A light Source which provides energy source with high output in the UV range (down to 165 nm)

A light Source which used above 800 nm

Beer's Law formula Where A= a= b= c=

A light Source which emits narrow bands of energy at well-defined places in the spectrum (UV and visible)

Glass prisms are for

are for the UV region in prism

A type of monochromator that Rays of radiant energy bend (refract) around the sharp edges of the grooves and Extent of refraction varies with the wavelength

A type of monochromator that the thickness of the layer determines the wavelength of energy transmitted and with Band pass of 10 – 20 nm

2 Types of Double Beam Spectrophotometer

w/ 2 photodetectors and all components are duplicated except the light source the beams of light pass-through different components but at the same time

Light Source consists of a gas tight chamber Containing anode, a cylindrical Cathode and inert gas such as helium or argon

Light Source produces a continuous source of radiation which covers both the UV and visible range. This is not suited for routine application as problems result from stray light

An Internal Component of Spectro – isolates a narrow beam of radiant energy; prevents stray light from entering the monochromator

Defines the range of wavelengths transmitted and is calculated as width at more than half the maximum transmittance

A type of monochromator that is Wedge-shaped pieces of glass, quartz, NaCl, that can be rotated

A type of monochromator that disperses white light into a continuous spectrum of colors by refraction

A type of monochromator most commonly used monochromator because it has better resolution.

A type of monochromator device that has small parallel grooves or slits and acts as prism (refract white light) and has slit (diffract it into several spectra)

Prism monochromator Principle

Diffraction Grating Monochromator Principle

A type of monochromator that has Colored glass or colored gelatin sandwiched between two glass plates

In TRANSMISSION FILTERS Light outside the transmission band is absorbed by the

The Band Pass of TRANSMISSION FILTERS

A type of monochromator that is Semi-transparent silver films on both sides of dielectric such as MgF. It is not expensive but precise

A type of monochromator that produces monochromatic light based on the principle of constructive interference of waves

An Internal Component of Spectro with an Internal Dimension of 1 Cm that holds the solution in which the absorption is to be measured

Other name for Photocell

Type of detector where it is a device whose electrical resistance decreases as the level of incident light is raised and do not require an external power source

Type of detector that has Cadmium sulfide or cadmium selenide are the light-sensitive materials typically used for the visible region

Type of detector that is capable of significantly amplifying a current and the cathode is a negative light-sensitive metal that absorbs light and emits electrons in proportion to the radiant energy that strikes the surface

Type of detector where electrons go to the dynodes, where electrons produce 4 – 6 additional electrons. The electrons are collected at a final electrode, the positive anode

Advantages of Photomultiplier tube

An Internal Component of Spectro Where electrical energy from a detector is displayed

A read out device where the output of the detector is used to drive a sensitive meter directly without further amplification

A read out device where the output of the detector is balanced against the output of a reference circuit

A read out device where numerical display of absorbance or converted values of concentrations

A read out device where

Type of Double Beam Spectrophotometer where All components are duplicated except the light source

Type of Double Beam Spectrophotometer where beams of light pass through different components but at the same time

Type of Double Beam Spectrophotometer that Uses a light beam chopper (a rotating wheel) – with alternate silvered sections and cut out sections, inserted after the exit slit.

It involves the measurement of emitted light when electrons in an atom become excited by heat energy produced by the flame. When these electrons return to their ground state, they emit light characteristic of the ions present.

Other name for flame photometry

It is used primarily to determine concentration of sodium, potassium or lithium since these alkali metals are easy to excite.

Color of alkali metals when excite letters only Sodium = Potassium = Lithium = Rubidium = Magnesium =

A component of Flame Photometer mixture of hydrogen and oxygen gas

Gases in Flame Photometry

Part of the Burner assembly where it draw sample into the flame

Part of the Burner assembly that creates a fine spray of sample solution to be fed into the flame of the burner

Part of the Burner assembly that provides heat energy for excitation

A type of Burner in Flame Photometry where aspirate sample directly into the flame, the gases are passed at high velocity over the end of the capillary suspended in the solution

A type of Burner in Flame photometry where involves the gravitational feeding of solution through a restricting capillary into an area of high velocity gas flow where small droplets are produced and passed into the flame

A component of Flame Photometer uses photocell as detector

MONOCHROMATOR where transmit yellow light (589 nm)

INTERFERENCE FILTERS Where it transmit violet light (767 nm)

INTERFERENCE FILTERS where it transmit red light (761 nm)

The Internal Standard in Flame Photometry

The element is not excited in the flame but merely dissociated from its chemical bond and placed in an unexcited state. The atom, at a lower energy level, absorbs light. The light source emits radiant energy to be absorbed by the element.

Measures the amount of light absorbed by ground state atom

AAS Used to measure element symbol only

Components of Flame Photometer

Components of AAS

Light Source in AAS which produces a wavelength of light specific for the kind of metal in the cathode

A component of AAS that modulates light beam coming from the hollow cathode lamp

A component of AASuses flame to dissociate the chemical bonds and form free, unexcited atoms

Type of Burner in AAS where flame is more concentrated and can be made hotter, thus lessening chemical interferences.

Type of Burner in AAS wheregases are mixed and the sample is atomized before entering the flame and the large droplets go to waste and not in the flame. It has less noisy signals with longer pathlength and greater absorption and sensitivity.

A component of AAS selects the desired wavelength from a spectrum of wavelength which could either be a prism or a diffraction grating.

A component of AAS uses photomultiplier tubes to measure the intensity of the light signal.

energy emission that occurs when certain compounds absorb electromagnetic radiation, become excited and then return to an energy level that is usually slightly higher than their original level.

FLUORESCENCE Components