Serum spectrophotometric analysis

An area worthy of study is the development of systems of increasing sample throughput beyond the single column operation. Scott has introduced a prototype multicolumn system based on the centrifugal analyzer principle (53). In this set-up a series of LC colimns is rotated on a disc, with sample delivery at the center of the disc and elution and spectrophotometric analysis on the outside. He has suggested using affinity columns for rapid serum protein analysis by this approach. Of course, other principles, such as segmented flow, could be envisioned in an automated LC system as well. Undoubtedly, we can expect to see the availability of such systems in the next few years. 

All other available methods for determining serum total proteins have been discussed above in relation to albumin, and their limitations indicated. All methods suffer from differences in the individual protein s contribution of the parameter being measured. However, the tyrosine (Folin-Ciocalteu) and arginine (Sakaguchi) equivalence methods (S7) and the near-ultraviolet spectrophotometric methods are more severely affected in this respect than other methods, and are therefore unreliable for total serum protein analysis. 

Limitations in colorimetric and atomic absorption spectrophotometric measures have prompted development of alternative methods of transition metal analysis. One example is the use of ion exchange chromatography to assess transition metals in serum and whole blood, a method developed by the company Dionex. While identification of transition metal complexes can also be made on the basis of symmetry (Laporte mle) or spin selection rule or analysis of charge transfer spectra, one of the most significant methods is on the basis of magnetism. The... 

The concentration of lithium in serum, plasma, urine, or other body fluids has been determined by flame emission photometry, atomic absorption spectrometry, or electro-chemically using an ion-selective electrode. Serum analysis, the most useful specimen for lithium monitoring, is most commonly quantified by automated spectrophotometric assay. 

A. T. Haj-Hussein and G. D. Christian, Multicomponent Flow Injection Analysis Using Spectrophotometric Detection with Reagent Spectral Overlap Application to Determination of Calcium and Magnesium in Blood Serum Using Eriochrome Black T. Microchem. J., 34 (1986) 67. 

Among the common metal ions, only aluminum and cobalt gave peaks when complexed with 8-quinolinol and eluted with SDS-acetonitrile mobile phases. However, the peaks appeared very close to each other with spectrophotometric detection (Fig. 12.2). The selective determination of aluminum was only possible with fluorimetric detection. The addition of SDS as well as several other surfactants to the aluminum complex solution, increased the fluorescence intensity. The procedure did not require deproteinization prior to analysis. The most commonly used technique for aluminum in human serum is graphite-furnace atomic absorption spectrophotometry, which is often limited due to serum matrix interference. 

A 30-year-old immunocompetent woman was given intravenous aciclovir 45 mg/kg/day for viral meningoencephahtis [17 ]. Acute renal insufficiency developed (serum creatinine 63 p.mol/1 on day 0, increasing to 385 p.mol/1 on day 12) urine analysis showed birefringent crystals, deemed typical of aciclovir-derived crystals on spectrophotometric examination. The renal dysfunction resolved after withdrawal of aciclovir and rehydration. 

The NADH produced is subsequently measured by spectrophoto-metric or fluorimetric detection. The characteristics of the main enzymatic assays are reported in Table 3. The first application of this prin ple to serum 3o(-hydroxy bile acids was reported by Iwata et al. in 1964. Using spectrophotometric determination of NADH at 340 nm, they found the lowest practical limit of detection to be approximately 0.01 j Amol in the final reaction mixture (3 ml). This implied that at least 20 ml of serum were needed for the analysis, introducing a high background and clinical imprati-cability. 

Saima et al. (2013) reported another Fl-spectrophotometric method for vitamins A and E analysis in pharmaceuticals, infant milk, and blood serum samples using a fer-rozine-Fe(II) detection system. In the presence of vitamin A/E, iron(III) was reduced to iron(II), then the in situ iron(II) reacted with ferrozine to produce a magenta-colored complex with an absorption wavelength of 562 nm. The limits of detection (3s) were 0.06 and 0.03 pg/mL with relative standard deviations (n = 4) in the range of 0.8%-2.8%, respectively. The method was validated by comparing with HPLC reported method (Driskell et al., 1982) and the results have shown that there was no significant difference between the two methods at 95% confidence level. 

The immobilization of pyranose oxidase and horseradish peroxidase in activated resins associated with a spectrophotometric reaction based on the formation of Bindshedler s green (k = ITl nm) permits the determination of sorbitol in a FIA format with a detection limit of 1.2 pmol L [62]. Prior to enzyme conversion, samples suffer an online treatment based on passage through a cleanup column filled with a strongly basic anion exchange resin, positioned after the injection valve. This step was of the utmost importance during the analysis of serum samples and can also be exploited for the analysis of foods and... 

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