INDEX standardization

Indexing standards solution of n-alkanes (C7 to C18 in 0.005% pentane see recipe)... 

Figure G1.1.2 An FID chromatogram of an indexing standard and parameters used to calculate retention indices. For equations, see Support Protocol, step 3.

Record the chromatogram as a retention index standard for all runs performed under the same operating conditions (unitgi.i). 

Inject 1 pi indexing standards solution of n-alkanes via a splitless injector and start the GC program. 

Use the data from the indexing standards to convert each time into a retention index... 

Run indexing standards and the first sample (highest concentration) as described (see Basic Protocol 1, steps 1 to 8). 

The results of the evaluation showed the RIs to vary only slightly with the different operator, the different instrument of the same manufacturer with the same column in one or several laboratories, column individuals of the same manufacturer, solvents (diethyl ether, acetone, and ethyl acetate), and use of a multistep temperature program. There were no significant differences in the reproducibility of RIs determined using different index standard series. M-standards are relatively nonpolar and differ little in their behavior from C-standards on a nonpolar SE-54 phase. When the number of index standard components was reduced, the RI values... 

A. Manninen, M.-L. Kuitunen and L. Julin. Gas chromatographic properties of the M-series of universal retention index standards and their application to pesticide analysis, J. Chromatogr., 394, 465-471 (1979). 

Warr LN, Nieto F (1998) Crystallite thickness and defect density of phyllosihcates in low-temperature metamorphic pelites A TEM and XRD study of clay mineral ciystalhnity-index standards. Can Mineral 36 1453-1474... 

There are fewer studies on the retention mechanism for open tubular columns but the theory presented for packed columns should be equally applicable. For films of normal thickness open tubular columns have a large surface area/volume ratio and the contribution of interfacial adsorption to retention will be significant for those solutes with limited solubility in the stationary phase [42]. Interfacial adsorption was shown to affect the retention reproducibility of polar solutes on non-polar stationary phases of different film thicknesses and the retention index values of solutes on polar stationary phases due to liquid phase interfacial adsorption of the n-alkane retention index standards [184,188,193-197]. 

Index Standard tension (KN) Sampling voltage (V) Measurement tension (KN) Error (KN)... 

ABSTRACT This article studies the basic principle of mine rescue training, and carries on system analysis from the aspects of physical indicators, physical index standards, exercise prescriptions, physical indicators quantitative scheme and so on. For the requirements of a certain rescue team members body function, flexibility quality and endurance quality, the writer designs training programs and empirical... 

Refractive Index. A Bausch and Lomb ABBE-3L refractometer was used to determine the refractive indices of thin films of the polymers. A refractive index standard of 1.440 0.0005 was used for calibration. A smooth surface polymer... 

Hydroperoxides determination is the key factor to measure the level and the behavior of the oxidation (Carlsson et al. 1987b, Lacoste and Carlsson 1991, Shen, Yu, and McKellop 1999). Scientific studies and the American Society for Testing and Materials (ASTM) oxidation index standard (ASTM F2102) usually give the quantity of ketones and other carboxyl species present as an index of the oxidation degree. It must be pointed out that ketones, though a product of the oxidative process, do not produce polymeric chain scissions and so they do not result in substantial reduction of tiie UHMWPE mechanical properties. Quantification of ketones is reliable only if the ratio between ketones and carboxylic acids remains constant through the entire oxidative process. 

While the paraffins represent a set of universal standards for establishing an index, other homologous series have been used in particular industries where other series are commonly used [4]. For example, four index systems have been compared recently for characterizing nitrogenous acidic and neutral drugs [5]. The alkylhydantoins and alkylmethylhydantoins turned out to be the most feasible retention index standards for the compounds studied. 

Schwarts, T.R. Petty, J.D. Kaiser, E.M. Preparation of n-alkyl trichloroacetates and their use as retention index standards in gas chromatography. Anal. Chem. 1983, 55, 1839-1840. 

Preparation of the Time Index Standard Mixture (FAMEs) Methyl caprylate, methyl pelargo-nate, methyl caprate, methyl laurate, methyl myristate, methyl palmitate, methyl stearate, methyl eicosanoate, methyl docosanoate, lignoceric acid methyl ester, methyl hexaco-sanoate, methyl octacosanoate, and triaconta-noic acid methylester. Alternatively, alkanes or fatty acids may also be used. The final concentration of each compound in the mixture should be between 0.4 and 0.8 mg/mL of chloroform. 

Use of M-series retention index standards in the identification of trichothecenes by electron impact mass spectrometry. 

Type of ichthyosis In vitrolin vivo measurement No. of patients or patient number from Table ) Labelling index standard deviation... 

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