Analysis simultaneous

A spcctruphoLornetric problem in simultaneous analysis (Ewing, 198.2) is taken from the original research of Weissler (194.2), who reaeted hydrogen peroxide with Mo, Ti, and V ions in the same solution to produce corn pounds that absorb light strongly in overlapping peaks with absorbances at. 320. 410. and 460 nrn, respectively as sliown in (Fig, 2-3),... 

As discussed earlier, the simultaneous analysis of samples containing two analytes requires the isolation of two precipitates. As shown in Example 8.2, conservation of mass can be used to write separate stoichiometric equations for each precipitate. These equations can then be solved simultaneously for both analytes. 

Selectivity The selectivity of atomic emission is similar to that of atomic absorption. Atomic emission has the further advantage of rapid sequential or simultaneous analysis. 

When the overlap between the voltammograms for two components prevents their independent analysis, a simultaneous analysis similar to that used in spectrophotometry may be possible. An example of this approach is outlined in Example 11.12. 

Ohta and Tanaka reported a method for the simultaneous analysis of several inorganic anions and the cations Mg + and Ca + in water by ion-exchange chromatography. The mobile phase includes 1,2,4-benzenetricarboxylate, which absorbs strongly at 270 nm. Indirect detection of the analytes is possible because their presence in the detector leads to a decrease in absorbance. Unfortunately, Ca + and Mg +, which are present at high concentrations in many environmental waters, form stable complexes with 1,2,4-benzenetricarboxylate that interfere with the analysis. 

The method described here is impractical when the simultaneous analysis of both A and B is desired. The difficulty in this case is that conditions favoring the analysis of A generally do not favor the analysis of B. For example, if conditions are adjusted such that 99% of A reacts in 5 s, then B must reach 99% completion in either 0.01 s if it has the faster kinetics or 2300 s if it has the slower kinetics. 

Strained set of lattice parameters and calculating the stress from the peak shifts, taking into account the angle of the detected sets of planes relative to the surface (see discussion above). If the assumed unstrained lattice parameters are incorrect not all peaks will give the same values. It should be borne in mind that, because of stoichiometry or impurity effects, modified surface films often have unstrained lattice parameters that are different from the same materials in the bulk form. In addition, thin film mechanical properties (Young s modulus and Poisson ratio) can differ from those of bulk materials. Where pronounced texture and stress are present simultaneously analysis can be particularly difficult. 

Pilot plant experiments vary over a wide range, aeeounting for industrial eonstraints (e.g., duration of operation, eontrol parameters, equipment reliability, and impurities in the raw materials). Seale-up problems are investigated during pilot plant experiments. A pilot plant is an experimental rig, whieh displays the part of the operation that eorresponds to an industrial plant. It allows for simultaneous analysis of the physieal and ehemieal meehanisms. A pilot plant is indispensable for measuring the extent of the possible interaetions between these two types of meehanisms. It ean be small to minimize extraneous eosts sueh as the total operation eost as well as other eonstraints. 

A. Kaunzinger, P. Podebrad, R Liske, B. Maas, A. Dietiich and A. Mosandl, Stereochemical differentiation and simultaneous analysis of 3-,4- and 5-hydroxyalkanoic... 

Figure 15.7 Cliromatographic separation of cliiral hydroxy acids from Pseudomonas aeruginosa without (a) and with (h) co-injection of racemic standards. Peak identification is as follows 1, 3-hydroxy decanoic acid, methyl ester 2, 3-hydroxy dodecanoic acid, methyl ester 3, 2-hydroxy dodecanoic acid, methyl ester. Adapted from Journal of High Resolution Chromatography, 18, A. Kaunzinger et al., Stereo differentiation and simultaneous analysis of 2- and 3-hydroxyalkanoic acids from hiomemhranes hy multidimensional gas cliromatog-raphy , pp. 191 -193, 1995, with permission from Wiley-VCH. (continuedp. 419)...

E. Podehrad, M. Heil, S. Leih, B. Geier, T. Beck, A. Mosandl, A. C. Sewell and H. Bohles, Analytical approach in diagnosis of inherited metabolic diseases maple syrup urine disease (MSUD)-simultaneous analysis of metabolites in urine by enantioselective multidimensional capillary gas chromatography-mass specti ometiy (enantio-MDGC-MS) , 7. High Resolut. Chromatogr. 20 355-362(1997). 

Column coupling proves to be a rapid screening approach in identifying chiral selectivity in the most efficient and economical way. In addition to the potential for the simultaneous analysis of a mixture, the coupling practice offers the advantages... 

Simultaneous analysis of neutral and acidic pharmaceuticals as well as related compounds by gas chromatography-tandem mass spectrometry in wastewater. Talanta 73 314-320... 

Batt AL, Aga DS (2005) Simultaneous analysis of multiple-classes of antibiotics by ion trap LC/MS/MS for assessing surface water and groundwater contamination. Anal Chem 77 2940-2947... 

The simultaneous analysis of orthophosphate, glycerol phosphates, and inositol phosphates has been achieved by spectrophotometric analysis of the molybdovanadate complexes. Also, a sensitive and selective chemiluminescent molecular emission method for the estimation of phosphorus and sulphur is described, which is based on passing solutions into a cool, reducing, nitrogen-hydrogen diffusion flame. For organic compounds it was usually necessary to prepare test solutions by an oxygen-flask combustion technique. 

GOTO T, YOSHIDA Y, Kiso M and NAGASHIMA H (1996) Simultaneous analysis of individual catechins and caffeine in green tea , J Chromatogr A, 749, 295-9. 

Frazierm, R.A. et ah. Development of a capillary electrophoresis method for the simultaneous analysis of colours, preservatives and sweeteners in soft drinks, J. 

Partial least squares regression (PLS). Partial least squares regression applies to the simultaneous analysis of two sets of variables on the same objects. It allows for the modeling of inter- and intra-block relationships from an X-block and Y-block of variables in terms of a lower-dimensional table of latent variables [4]. The main purpose of regression is to build a predictive model enabling the prediction of wanted characteristics (y) from measured spectra (X). In matrix notation we have the linear model with regression coefficients b ... 

In Section 8.2.8 we have discussed the standard addition method as a means to quantitate an analyte in the presence of unknown matrix effects cf. Section 13.9). While the matrix effect is corrected for, the presence of other emalytes may still interfere with the analysis. The method can be generalized, however, to the simultaneous analysis of p analytes. Multiple standard additions are applied in order to determine the analytes of interest using many q > p) analytical sensors. It... 

The determination of orbencarb in crops and soil is conducted by simultaneous analysis with its metabolites. In crops, orbencarb, I and II are extracted with acidic ... 

The most general method for the simultaneous analysis of oxyanions by gas chromatography is the formation of trimethylsilyl derivatives. Trimethylsilyl derivatives of silicate, carbonate, oxalate, borate, phosphite, phosphate, orthophosphate, arsenite, arsenate, sulfate and vanadate, usually as their ammonium salts, are readily prepared by reaction with BSTFA-TMCS (99 1). Fluoride can be derivatized in aqueous solution with triethylchlorosilane and the triethylfluorosilane formed extracted into an immiscible organic solvent for analysis by gas chromatography [685). 

Y. Nicolas, M. Paques, A. Knaebel, A. Steyer, J.-P. Munch, T. B. J. Blijdenstein, G. A. van Aken 2003, (Microrheology structural evolution under static and dynamic conditions by simultaneous analysis of confocal microscopy and diffusing wave spectroscopy), Rev. Sci. Instrum. 74, 3838. 

Floridi, A., Palmerini, C. A., and Fini, C., Simultaneous analysis of bases, nucleosides, and nucleoside mono- and polyphosphates by high-performance liquid chromatography,. Chromatogr., 138, 203, 1977. 

While additive analysis of polyamides is usually carried out by dissolution in HFIP and hydrolysis in 6N HC1, polyphthalamides (PPAs) are quite insoluble in many solvents and very resistant to hydrolysis. The highly thermally stable PPAs can be adequately hydrolysed by means of high pressure microwave acid digestion (at 140-180 °C) in 10 mL Teflon vessels. This procedure allows simultaneous analysis of polymer composition and additives [643]. Also the polymer, oligomer and additive composition of polycarbonates can be examined after hydrolysis. However, it is necessary to optimise the reaction conditions in order to avoid degradation of bisphenol A. In the procedures for the analysis of dialkyltin stabilisers in PVC, described by Udris [644], in some instances the methods can be put on a quantitative basis, e.g. the GC determination of alcohols produced by hydrolysis of ester groups. 

Simultaneous analysis of C, H, and N in liquid or solid organic materials may be carried out after combustion in an oxygen atmosphere at temperatures up to 1000 °C. The gaseous combustion products (CO2, H2O, N2) are flushed with a carrier gas (helium) through a reductant, and quantification is obtained by GC. For analysis of O, the combustion is performed in helium over platinised carbon. Carbon monoxide formed is converted to CO2 by passage over CuO, and measured in the same manner as for analysis of C. A 2-3 mg sample is required. 

For the simultaneous analysis of n components, at least N > n useful signals must be available. Instrumental-analytical methods produce as a rule two-dimensional information y = /(z), e.g., in form of spectra, chromatograms etc., as schematically shown in Fig. 7.11. 

Sanchez, J-C., Wirth, P., Jaccoud, S., Appel, R.D., Sarto, C.Wilkins, M.R., Hochstrasser, D.F. (1997). Simultaneous analysis of cyclin and oncogene expression using multiple monoclonal antibody immunoblots. Electrophoresis 18, 638. 

---