Instant Notes: Analytical Chemistry

of individual elements present may be identified. This is the technique of ICP- E14 Mass spectrometry Quantitative measurements ...

focused on it, and hydride generation (Topic E7) are also used. Electrothermal vaporization may also be employed for solids. As ...

ions occur at the same m/zratio as the analyte ion. For example,^32 S^16 O+and (^31) P (^16) O (^1) H+both interfere with (^48) ...

E5 – Inductively coupled plasma spectrometry 213 Table 1. Detection limits for atomic emission spectrometry/ppb (mg l-^1 ) Eleme ...

Section E – Spectrometric techniques E6 X-RAY EMISSION SPECTROMETRY Principles Each element has electrons occupying specific ene ...

1/l=a(Z -b)^2 For example, the copper-Ka 1 line has a wavelength of 0.154 nm, and Z =29, whereas for nickel the values are 0.166 ...

characteristic of the elements in it. These are diffracted by a crystal analyzer, for example lithium fluoride, or quartz, which ...

Applications The detection and measurement of the elements present in a sample is valuable and an example in Figure 3shows the a ...

Section E – Spectrometric techniques E7 ATOMIC ABSORPTION AND ATOMIC FLUORESCENCE SPECTROMETRY Principles The energy levels of a ...

analyzed, for example, a zinc source lamp to determine zinc. These are called resonance linesources, and may be a hollow cathode ...

Electrodeless discharge lamps have a small, sealed cavity containing a minute amount of the element to be measured, or its salt. ...

for this is important. This can be accomplished by using a deuterium lamp as a source of continuous radiation and by modulating ...

commercially available as 1000 ppm certified standards in dilute perchloric acid. Organic solvents, such as white spirit (~C10 a ...

Section E – Spectrometric techniques E8 ULTRAVIOLET AND VISIBLE MOLECULAR SPECTROMETRY: PRINCIPLES AND INSTRUMENTATION The ultra ...

correspond to the pbonding and p* antibonding orbitals. Bonding orbitals have lower energy, while antibonding orbitals have high ...

higher energy level (Fig. 2). Usually the spins are still opposed, so this is an excited singlet state, S 1. Deactivation may th ...

quantitative analysis. An example of a filter system is a modern fiber-optic photometer. Light from a tungsten lamp passes down ...

As noted in Topic E2, the fluorescent intensity, IF, is directly proportional to the concentration, c, provided that the absorpt ...

Section E – Spectrometric techniques E9 ULTRAVIOLET AND VISIBLE MOLECULAR SPECTROMETRY: APPLICATIONS Structure effects The struc ...

between the highest filled plevel and the lowest empty p* level is smaller, and hence the wavelength of that absorption is great ...