Instant Notes: Analytical Chemistry

Example 2 The spectra shown in Figs 2(a)−(d)are for a liquid, boiling at 141°C and soluble in water. The elemental composition w ...

F2 – Sample identification using multiple spectrometric techniques 291 4000 3000 2000 1500 1000 500 %T cm–1 100 50 (^004080120) ...

292 Section F – Combined techniques Example 3 The spectra shown in Figures 3(a)–(d)are for a compound boiling at 205°C and insol ...

While these three examples are relatively simple, they illustrate the advantages of the multidisciplinary approach in the analys ...

Section F – Combined techniques F3 GAS CHROMATOGRAPHY- MASS SPECTROMETRY Principles The separation of mixtures by gas chromatogr ...

and is removed by pumps, while the larger sample molecules continue through into the MS. A complete GC-MS system is shown in Fig ...

Mixtures of fragrances are readily analyzed. Figure 2 shows the TIC chromatogram of a mixture of six fragrance components, injec ...

animals) and of pyrethrin insecticides using field ionization MS. Pharmaceutical samples such as antibiotics can be studied, but ...

Section F – Combined techniques F4 GAS CHROMATOGRAPHY- INFRARED SPECTROMETRY Principles Chromatographic techniques (Section D) a ...

employed. A nonpolar stationary phase (e.g. a silicone), which separates compounds chiefly according to their boiling points, is ...

Applications A gas chromatogram obtained from a few microliters of a 12-component mixture is shown in Figure 2. As with infrared ...

absorbance of a particular peak in the spectrum, or integrating the total IR absorbance over a range, an infrared chromatogramma ...

Section F – Combined techniques F5 LIQUID CHROMATOGRAPHY- MASS SPECTROMETRY Principles The wide variety of modes of liquid chrom ...

obtained by applying a potential difference of 3−6 kV between the tube and a counter electrode. The drops accumulate charge on t ...

304 Section F – Combined techniques 0 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 Time (min) m/z 18.00 20.00 22.00 24.00 26.00 2 ...

Section G – Thermal methods G1 THERMOGRAVIMETRY Principles One of the simplest tests that may be applied to an analytical sample ...

better to use the fraction reacted, a, instead of concentration, and for a simple (first order) reaction the rate may be written ...

When a complex mass loss occurs, involving several reactions, matters become more complicated. Calcium oxalate monohydrate, CaC ...

● the sample and its container; ● the sensors for measuring temperature and the sample property; ● the computer, data collection ...

● the crucibleor container, its size, shape and material; ● the rate of heatingand any special program; ● the atmosphere, and wh ...