Computerized data handling

Modern mass spectrometers are interfaced with computerized data handling sys terns capable of displaying the mass spectrum according to a number of different for mats Bar graphs on which relative intensity is plotted versus m z are the most common Figure 13 40 shows the mass spectrum of benzene m bar graph form... 

The major or minor elements in coal ash can be determined using XRF techniques. Detector output is converted into concentration by computerized data-handling equipment. All elements are determined, including Fe, Ca, K, Al, Si, P, Mg, Ti, and Na. These elements can also be determined by atomic absorption (AA) spectrophotometry. 

Data System Setup Set the integrator or computerized data-handling system as its respective manual instructs for normal gel permeation chromatographic determinations. Set the integration time to 15 min. 

Optical spectroscopies are appropriate for many process analysis applications because they can provide a rapid analysis of process stream composition in an industrially robust form requiring little regular maintenance. On-line implementation means that extracting manual samples is avoided and results obtained using computerized data handling methods can be hnked to automatic control schemes. Recently a review of spectroscopy in process analysis has been published which contains descriptions and describes applications of optical spectroscopies [2]. 

Some advantages of QELS include (1) rapid analysis time (2) wide range 0.003-5 pm (3) minimal sample handling (4) only refractive index and viscosity of cUspersing media are required (S) small sample size (2 ml or less) (6) any transparent dispersion medium is acceptable (7) no instrument calibration (8) computerized data handling (9) suitable for stabili measurements (10) hi precision. 

The combination of GC-MS and computerized data handling systems has proved to be one of the most powerful analytical methods for identifying minute (10 g) components which may be present in chemical samples. The greatest success has been in its application in the fields of forensic science, pollution, and biochemistry. 

The customer will advise on the format of the advanced shipment notification (ASN). A computerized system will give you flexibility such that you are able to transmit the information immediately the shipment is loaded. You could use a fax machine as your backup since transmission is nearly as fast but this is likely to present the customer with data-handling problems. A computerized transmission feeds the data directly onto the customer database, by-passing the manual data-entry stage. Your backup system should do the same in order that your customer perceives no noticeable change in the information. 

The outline of the construction of a typical plasma emission spectrometer is to be seen in Figure 8.10. The example shown has an inductively coupled plasma, excitation source, but the outline would be similar were a dc source to be fitted. Different combinations of prisms and diffraction gratings may be used in the dispersion of the emitted radiation, and in the presentation of the analytical signal. Instruments are computerized in operation and make use of automatic sample handling. Sophisticated data handling packages are employed routinely to deal with interferences, and to provide for clarity in data output. 

There can be no doubt that instrumental methods of analysis have revolutionized analytical chemistry, in terms of increased sensitivity, more rapid throughput, multielement capability, computerized calibration, and data handling, etc. There is a cost, too, of course - increased capital expenditure, increased instrumental complexity, and, above all, the current tendency to believe implicitly the output of a computer. Just because a machine gives an analysis to 12 places of decimals doesn t mean that it is true (see Chapter 13) ... 

Detect and record the separated ions. Multipliers are the most common detectors used in LC-MS instruments. Proper fully computerized data manipulation systems are required to handle the massive information flux from the detector. 

Major advancements in mass spectrometric instrumentation (e.g., ESI and MALDI) and electronics (e.g., TOE data handling) have been accompanied by rapid progress in computerization. Older mass spectrometrists may still remember when hand-adjusted potentiometers were used to manipulate the ion beam, and spectra were collected on photographic paper where the peaks had to be counted by hand (using... 

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