Quantitation in situ

The amino derivatives of amitriptyline and nortriptyline produced at the second heating stage exhibit intense pale yellow fluorescence on examination in long-wavelength UV light (X,= 365 nm), but this is not sufficiently reproducible for quantitative in situ work. 

In situ quantitation Direct measurement of the UV absorption at wavelength X = 280 nm was preferred for quantitative in situ evaluation since the reagent treatment did not yield more exact results. 

In situ quantitation The reagent was not suitable for quantitative in situ evaluations. 

In situ quantitation The fact that the colors of the chromatogram zones changed means that quantitative in situ evaluation is only meaningful in rare cases. 

An important point is that these advances have been complemented by the concomitant development of innovative pulse-characterisation procedures such that all the features of femtosecond optical pulses - their energy, shape, duration and phase - can be subject to quantitative in situ scrutiny during the course of experiments. Taken together, these resources enable femtosecond lasers to be applied to a whole range of ultrafast processes, from the various stages of plasma formation and nuclear fusion, through molecular fragmentation and collision processes to the crucial, individual events of photosynthesis. 

Ambesi-Impiombato A, D Urso G, Muscettola G, de Bartolomeis A. 2003. Method for quantitative in situ hybridization histochemistry and image analysis applied for Homer la gene expression in rat brain. Brain Res Prot 11 189-196. 

Key M, WirickB, Cool D, Morris M. 2001. Quantitative in situ hybridization for peptide mRNAs in mouse brain. Brain... 

Vizi S, Gulya K. 2000. Calculation of maximal hybridization capacity (Hmax) for quantitative in situ hybridization a case study for multiple calmodulin mRNAs. J Histochem... 

Soe MJ, Okkels F, Saboimn D et al (2011) HistoFlex—a microfluidic device providing uniform flow conditions enabling highly sensitive, reproducible and quantitative in situ hybridizations. Lab Chip 11 3896-3907... 

Separation of a number of keto acid hydrazones may be accomplished as their free hydrazones [37], as sodium salts [38] or as ammonium salts [39]. For TLC separation of the sodium salts a plate (20 X 20 cm) is coated with a 0.25-mm layer of a mixture of silica gel and 0.1 N sodium bicarbonate (1 2 w/v). The plate is activated by heating at 110 °C for 40 min and is then cooled and kept in a desiccator until required. The solvent systems are ethyl acetate (saturated with 0.1 N sodium bicarbonate)-methanol (5 1) and butanol-ethanol-0.1 N sodium bicarbonate (10 3 10) (upper layer). The plates are developed for 2.5 h at room temperature. For quantitation, the spots may be removed from the plate and dissolved in 2.07V sodium hydroxide for color development and determination in solution. Treatment of the plate directly with base (as a spray) should also be possible for quantitation in situ. The wavelengths of the absorption maxima of a number of DNPH-keto acids in aqueous base are listed in Table 4.6... 

The separation of transition-metal complexes of pyridine-2-carbaldehyde 2-quinolylhydrazone (PAQH) has been accomplished by TLC [63]. The method consists of separation of the metals as their PAQH chelates and quantitation in situ by reflectance spectroscopy. 

Method. The antibiotics are separated on silica gel G with chloroform-methanol (3 1). The plate is then dried in air and sprayed until the surface is saturated with 2.0 M ammonium bisulfate (aqueous). The plate is dried in air for ca. 1 h before quantitation in situ. Excitation is carried out at 300 nm, and all of the light which is emitted is recorded. The method is sensitive to amounts of less than 10 ng per spot. 

T. Niwaguchi and T. Inoue, Studies on quantitative in situ fluor-metry of lysergic acid diethylamide (LSD) on thin-layer chromatograms, J. Chromatogr., 59 121 (1971). 

Quantitative in-situ evaluation of the bromophos-ethyl and dimethoate separation in this case of visualization has no real value on account of the rather non-homogeneous background colouration produced by spraying with the detection reagent used here. Therefore the routine, quantitative in-situ evaluation of the unstained bromophos-ethyl and dimethoate in our laboratory is carried out by UV measurement in reflectance mode. 

The use of GC-MIP-AES is advantageous because it avoids the predecomposition step required in the AAS detection mode. The first applications of the MIP-AES detector for Hg speciation and detection were reported in the 1970s [27-29]. Despite the overall good detection ability of the detectors, however, most of the above methods require large sample volumes, tedious solvent extraction procedures, and usually lead to the final determination of only the Me-Hg species. The description of the feasibility of quantitative in situ aqueous ethylation of Hg2-1- and Me-Hg followed by on-line preconcentration and detection by atomic fluorescences pectro-metry (AFS) or AAS certainly produces a wealth of information since it allows all Hg species to be detected in the same chromatographic run. Also on-line speciation of Hg and Me-Hg by chromatography-AFS hydride generation (HG) was used [30]. 

Attenuated total reflectance Eourier-transform infrared (ATR-ETIR) spectroscopy is another technique recently reported to have been applied to the determination of pesticide residues on human skin and residential surfaces (Doran et al., 2000). While this technique gave good results when evaluated in the laboratory for three pesticides at 0.5 to 5 Rg/m skin loadings, field use would be very limited by the size and transportability of the instrument and the liquid-nitrogen coolant for the detector. Whatever the method, surface residues are also difficult to measure quantitatively in situ, especially on the skin. 

The temperature range is between 170 and 210 °C and the pressure may vary between 15 and 25 MPa. Altering these conditions will considerably change the composition of the reaction mixture. The authors were able to show that Raman. spectroscopy is a very suitable method for quantitative in situ analysis of the synthesis of this substance. 

The alkaloid contents in a single alkaloid cell from M. cordata roots of three different thicknesses (age 1-2 years) were determined as follows. The liquid from various numbers of alkaloid cells (Table II) was removed uniformly and collected in the microtrap. The liquid in the capillary and connection tubes was washed into the microtrap to make a certain definite volume for analysis. Quantitative analysis of each alkaloid was carried by preparing a calibration graph (4). Figure 3 shows the HPLC chromatogram of alkaloids from the alkaloid cells. The content of each alkaloid per single alkaloid cell in tissues from three different thickness of roots and its ratio are shown in Table II. The liquid in colorless cells contained only a minute amount of protopine and allocryptopine (Fig. 3). The thicker the roots, the more alkaloids were contained in a single alkaloid cell. In any thickness of root, the content of protopine-type alkaloids exceeded that of benzo[c]phenanthridine-type alkaloids. The ratio of the former to the latter was almost steady over 5 mm of root thickness (86-87%). The ratio of alkaloids in methanol extracts of the same fresh samples (thickness 5 mm) was determined by HPLC (Table III). The ratio of protopine-type alkaloids in the methanol extracts ( 80%) was less than that in the liquid from the alkaloid cells ( 87%). This was because the liquid in alkaloid cells near the cambium were picked up more than that in center cells (pith). Thus, intracellular components scattered in different places are analyzed qualitatively and quantitatively in situ by HC. 

Kong, J., and Ringer, D. P. (1995) Quantitative in situ image analysis of apoptosis in well and poorly differentiated tumor from rat liver. Am. J. Pathol. 147(6), 1626-1632. 

P MacLaurin, NC Crabb, I Wells, PJ Worsfold, D Coombs. Quantitative in situ monitoring of an elevated temperature reaction using a water-cooled mid-infrared fiber-optic probe. Anal Chem 68 1116-1123, 1996. 

While our Raman spectroscopic method is useful for the identification of the solid reaction products and the analysis of surface products, it is not suitable for direct, total quantitative in situ analysis of solids. 

TLC is useful both as an analytical and a preparative technique, and substances tentatively identified by TLC may be further characterized by various analytical techniques such as nuclear magnetic resonance spectrometry, mass spectrometry, or gas liquid chromatography. Moreover, many specific chemical detection tests are available to help identify substances separated by TLC. TLC is a microanalytical procedure and provides for separations and at least tentative identification of substances in the milligram (mg), microgram (/ig), and nanogram (ng) range. TLC can provide the biochemist with a method of eluting separated substances from plates for quantitative analyses. Recent studies indicate that elution techniques may not be the best alternative for quantitative analyses of many substances separated by TLC and that the preferred method may involve quantitative in situ densitometric analysis [1,2]. 

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