Operating limits sample tables

Another aspect of cost reduction would be solvent economy. The need to preferentially select inexpensive solvents and employ the minimum amount of solvent per analysis would be the third performance criteria. Finally, to conserve sample and to have the capability of determining trace contaminants, the fourth criterion would be that the combination of column and detector should provide the maximum possible mass sensitivity and, thus, the minimum amount of sample. The performance criteria are summarized in Table 1. Certain operating limits are inherent in any analytical instrument and these limits will vary with the purpose for which the instrument was designed. For example, the preparative chromatograph will have very different operating characteristics from those of the analytical chromatograph. 

The following appendix includes two samples for formatting operating limits tables. These can be customized to meet your facility s specific requirements. These samples also demonstrate the interaction between operating limits tables and procedures. The required actions in the tables can either be the actual required steps with all necessary e q)lanatory information or a reference to the applicable procedure. The steps or references to procedures should follow the development criteria listed in Chapter 5. 

Internal column diameters for fused silica range from 100 to 530 micrometers (0.10-0.53 mm). Some glass capillaries have even larger internal diameters. One-hundred micrometer columns, row one of Table 6.2, have limited sample capacity, and are not well suited for trace analysis. Ease of operation is also limited because of the very limited sample capacity. These small i.d. columns have very good efficiency and produce fast analyses (see Fig. 6.6), but special sampling techniques and high-speed data systems are required to realize their full potential. 

With conventional nonspectroscopic detectors, other methods must be used to identify the solutes. One approach is to spike the sample by adding an aliquot of a suspected analyte and looking for an increase in peak height. Retention times also can be compared with values measured for standards, provided that the operating conditions are identical. Because of the difficulty of exactly matching such conditions, tables of retention times are of limited utility. 

Table 12-4 is a summary of liquid fuel speeifieations set by manufaeturers for effieient maehine operations. The water and sediment limit is set at 1% by maximum volume to prevent fouling of the fuel system and obstruetion of the fuel filters. Viseosity is limited to 20 eentistokes at the fuel nozzles to prevent elogging of the fuel lines. Also, it is advisable that the pour point be 20 °F (11 °C) below the minimum ambient temperature. Failure to meet this speeifieation ean be eorreeted by heating the fuel lines. Carbon residue should be less than 1% by weight based on 100% of the sample. The hydrogen eontent is related to the smoking tendeney of a fuel. Lower... 

The procedure for the determination of total secondary alkanesulfonates with TLC and of total monosulfonates specified as homologs and isomers by derivatization GC-MS is shown in Fig. 18. The specific clean-up for sewage sludges prior to total secondary alkanesulfonate determination is outlined in Fig. 19. TLC conditions are given in Table 9. The limits of the quantification of secondary alkanesulfonates are summarized in Table 10. For eight samples and one operator the TLC time schedule is 4 days sample pretreatment and sublation, clean-up, TLC performance, and quantitative evaluation of TLC [24]. 

In addition, each workbook contained a summary table of all results and limit of detection (LOD) determinations. The table was organized with sample identifications in the left-hand column. Eor each analyte, the analytical result and the LOD appeared in adjacent columns, and analyte recoveries appeared above the results columns. The summary table was generated automatically from the analytical results in the individual worksheets, without operator intervention or re-entry of any information. 

A powerful advantage of SFC is that more detectors can be interfaced with SFC than with any other chromatographic technique (Table 4.30). There are only a few detectors which operate under supercritical conditions. Consequently, as the sample is transferred from the chromatograph to the detector, it must undergo a phase change from a supercritical fluid to a liquid or gas before detection. Most detectors can be made compatible with both cSFC and pSFC if flow and pressure limits are taken into account appropriately. GC-based detectors such as FID and LC-based detectors such as UVD are the most commonly used, but the detection limits of both still need to be improved to reach sensitivity for SFC compatible with that in LC and GC. Commercial cSFC-FID became available in... 

Table 7.33 reports the main characteristics of GC-ICP-MS. Since both GC and ICP-MS can operate independently and can be coupled within a few minutes by means of a transfer line, hyphenation of these instruments is even more attractive than GC-MIP-AES. GC-ICP-MS is gaining popularity, probably due to the fact that speciation information is now often required when analysing samples. Advantages of GC-ICP-MS over HPLC-ICP-MS are its superior resolution, resulting in sharper peak shapes and thus lower detection limits. GC-ICP-MS produces a dry plasma when the separated species reach the ICP they are not accompanied by solvent or liquid eluents. This reduces spectral interferences. Variations on the GC-ICP-MS... 

DCP-AES can be used for high-viscosity matrices, slurries, etc. Organic solvents and acids can be handled without problems. Sample preparation is simpler than for ICP. Operating costs are much lower than for ICP-AES. Table 8.32 compares DCP-AES to ICP-AES and FAAS Table 8.33 shows typical detection limits. DCP and its applications were reviewed [208]. 

Flame emission spectrometry is used extensively for the determination of trace metals in solution and in particular the alkali and alkaline earth metals. The most notable applications are the determinations of Na, K, Ca and Mg in body fluids and other biological samples for clinical diagnosis. Simple filter instruments generally provide adequate resolution for this type of analysis. The same elements, together with B, Fe, Cu and Mn, are important constituents of soils and fertilizers and the technique is therefore also useful for the analysis of agricultural materials. Although many other trace metals can be determined in a variety of matrices, there has been a preference for the use of atomic absorption spectrometry because variations in flame temperature are much less critical and spectral interference is negligible. Detection limits for flame emission techniques are comparable to those for atomic absorption, i.e. from < 0.01 to 10 ppm (Table 8.6). Flame emission spectrometry complements atomic absorption spectrometry because it operates most effectively for elements which are easily ionized, whilst atomic absorption methods demand a minimum of ionization (Table 8.7). 

The manifold for hydride generation is shown in Fig. 12.7. The operating conditions are as follows forward power 1400W, reflected power less than 10W, cooling gas flow 12L nr1, plasma gas flow 0.12L nr1, injector flow, 0.34L m 1. The standard deviation of this procedure was 0.02pL 1 arsenic and the detection limit O.lpg L-1. Results obtained on a selection of standard reference sediment samples are quoted in Table 12.14. 

Indoor air The most abundant OPFRs in indoor air samples from homes were TEP, T BP, TnBP, TCEP, and TC/PP, which are outlined in Table 3. Heavier OPERs such as TBEP, TPP, TCP, TDC/PP, and TEHP are usually present in low concentrations or even below the detection limit. However, in some work environments and cars high levels of TBEP and TDC/PP were observed [66, 68, 84]. The higher air concentrations were associated with a higher dust concentration... 

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