Total chromatographable organics

Additional analysis of these samples using the liquid chromatographic separation, total chromatographable organics, infrared, and low resolution mass spectrometry demonstrated that the sampling and analysis scheme produced reproducible data as shown in Table IV. 

Additions have been made to Chapters 1 and 2 in order to include more recent developments in techniques (e.g. Schlenk-type, cf p. 10), and chromatographic methods and materials. Chapter 3 still remains the core of the book, and lists in alphabetical order relevant information on ca 4000 organic compounds. Chapter 4 gives a smaller listing of ca 750 inorganic and metal-organic substances, and makes a total increase of ca 13% of individual entries in these two chapters. Some additions have also been made to Chapter 5. 

A mixture of 3.18 g (10 mmoles) of 17 -hydroxy-2-hydroxymethylene-5a-androstan-3-one, 20 ml dry dimethyl formamide and 0.3 g (13 mmoles) of sodium hydride is stirred for 0.5 hr at room temperature under nitrogen. A total of 1.51 g (12.5 mmoles) of redistilled allyl bromide is added and the mixture is stirred for 1 hr on the steam bath. Aqueous potassium hydroxide (2 g in 5 ml of water) is added and stirring is continued for 1 hr on the steam bath. The reaction mixture is diluted with 50 ml of methylene dichloride followed by careful addition of 300 ml of water. The organic phase is separated and the aqueous phase is again extracted with 50 ml of methylene dichloride. The combined extracts are washed with water, dried over sodium sulfate, filtered and chromatographed on 200 g of silica gel. Elution with pentane-ether (4 1) provides 2a-allyl-17j -hydroxy-5a-androstan-3-one 0.85 g (26%) mp 118-119° [aj 14° (CHCI3), after crystallization from ether-hexane. 

Wilson et al. [662-665] have described various prototype systems for total organic analysis devices. It has proved technically feasible to obtain UV, IR, NMR and MS spectra (together with atomic composition based on accurate mass determination) following RPLC separation. The fully integrated approach offers the benefit that one chromatographic run is required, thus ensuring that all of the spectrometers observe the same separation. Such multiple hyphenations might favour the analysis of complex mixtures for both confirmation of identity and structure determination (should this represent a cost-effective approach). Table 7.72 illustrates the main features of on-flow multiple LC hyphenation. 

Chromatographic separation and mass spectrometry are necessary to identify and measure quantitatively individual organic halogen components, but these are not practical for routine assay, and more general measurements are usually used. The first is the measurement of total organohalogen (TOX), and the second is of adsorbable organohalogen (AOX). These methods are based upon the principle... 

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