Wickbold combustion

The Wickbold combustion technique is suitable for processing liquid combustible samples such as petroleum products, which are difficult to decompose by other techniques [178]. In the Wickbold combustion system, an oxygen-hydrogen flame is used for sample decomposition at high temperatures (2000 °C). Liquid samples are directly introduced to the flame, whereas solid samples require a preliminary... 

A Wickbold combustion apparatus (V5 Heraeous, Germany) is commercially available. 

The lamp combustion method (ASTM D-1266, IP 107) and the Wickbold combustion method (IP 243) are used for the determination of sulfur in petroleum and as trace quantities of total sulfur in petroleum products and are related to various other methods (ASTM D-2384, ASTM D-2784, ASTM D-2785, ASTM D-4045)... 

Table 12.III. Recovery of Mercury by Wickbold Combustion Method...

Wickbold Combustion—Cold-Vapor Atomic Absorption Method... 

Outline of Method. A sample is weighed into a beaker, dissolved in benzene 2-propanol, and burned in an oxy-hydrogen flame using a Wickbold combustion apparatus. The combustion products are collected in a 5% sulfuric-nitric acid mixture containing potassium permanganate. Prior to measurement, trapped mercuric salts are reduced to elemental mercury with tin (II) chloride. The mercury is then swept out of solution and measured by cold-vapor atomic absorption spectroscopy. 

Wickbold combustion apparatus (Figure 12,2), This consists of a 250-ml sample reservoir, stainless steel burner, quartz combustion chamber, gas pressure regulators for oxygen, nitrogen, and hydrogen, and an absorber fitted with an extra-coarse frit (Koehler Instrument Co.). 

Wickbold Combustion. Recoveries approximating 50% were obtained by the combustion of spiked crude oils in a Wickbold burner using either dilute hydrochloric acid or hydrogen peroxide as the absorbing solution. Subsequent studies suggested that the low recovery was caused by the loss of selenium through adsorption on the walls of the hot combustion tube. The losses by adsorption appeared to be independent of sample matrix and to occur in essentially all petroleum samples. Consequently, no further studies on the Wickbold combustion technique were carried out. 

Hoppstock K and Michulitz M (1997) Voltam-metric determination of trace Pt in gasoline after wickbold combustion. Anal Chim Acta 350 135-140. 

Kotz etal. (1972, Decomposition of biological materials for the determination of extremely low contents of trace elements in limited amounts with nitric acid under pressure in a Teflon tube) Hartstein et al. (1973, Novel wet-digestion procedure for trace-metal analysis of coal by atomic absorption) Jackson etal. (1978), Automated digestion and extraction apparatus for use in the determination of trace metals in foodstuffs) Campos etal. (1990, Combustion and volatilization of solid samples for direct atomic absorption spectrometry using silica or nickel tube furnace atomizers) Erber et al. (1994, The Wickbold combustion method for the determination of mercury under statistical aspects) and Woit-tiez and Sloof (1994, Sampling and sample preparation). 

Erber D, Quigk L, Winter F, Roth J and Cam-mann K (1994) The Wickbold combustion method for the determination of mercury under statistical aspects. Eresenius J Anal Chem. 349 502-509. 

Wickbold combustion apparatus (combustion in an oxygen-hydrogen flame DIN 51400 Part I) (Fig. 118)... 

Total chlorides can be determined by the Schoniger method, which is rapid and utilizes small samples, and by the Wickbold method, which can be utilized for polymers as solids or liquids which may be aspirated into the combustion chamber as solutions in a suitable solvent. The Paar bomb or Wickbold combustion techniques are particularly amenable to the analysis of urethanes. 

Figure 5. Wickbold combustion apparatus a) Injection burner b) Combustion chamber c) Condenser d) Multiport stopcock e) Absorption chamber f) Flushing port...

Erber, D., Roth, J., and Cammann, K. (1997) Quality assurance system for a decomposition method as demonstrated for the Wickbold combustion technique. Accred. Qual. Assur, 2, 332-7. 

Total sulfur NF EN 24260 ISO 4260 ASTM D 2785 Combustion in Wickbold burner and analysis... 

Combustion Calorimetric bomb (Berthelot), oxygen flask (Schoniger), Wickbold apparatus, cold plasma incinerator, micro-Dumas combustion (CHN analyser), sulfur-specific analysers (S, C, N, O), pyrochemiluminescence... 

In the Wickbold method, solid samples are vaporised in an oxygen stream and fed into an oxyhydrogen flame, which bums in a cooled quartz tube. The combustion products are condensed here, or are captured in an absorption solution as gaseous materials. Although combustion in a Wickbold apparatus is a quick and effective method for destroying organic material of all types, incomplete destruction may occur [19]. In special digestion vessels, known as cold-plasma ashers (CPA),... 

ASTM D126 IP 107) that uses a modification of the standard wick-fed lamp. Many laboratories use rapid combustion techniques with an oxyhydrogen flame in a Wickbold or Martin-Floret burner (ASTM D2784 IP 243). 

One of the oldest methods in the literature for the measurement of organic fluorine compounds is the Wickbold method [125], where organic fluorine is converted to hydrogen fluoride via combustion. The Wickbold method is useful for determining the total organic fluorine content of a sample, but is nonspecihc and does not provide information on individual fluorinated molecules. In addition, for samples containing PFCs, the combustion may lead to incomplete decomposition and subsequent underestimation of the total fluorine content of the sample [125]. 

Analytical methods are available in standard form for determining volatile sulfur content and certain specific corrosive sulfur compounds that are likely to be present. Volatile sulfur determination is made by a combustion procedure (ASTM D-126, IP 107) that uses a modification of the standard wick-fed lamp. Many laboratories use rapid combustion techniques with an oxy-hydrogen flame in a Wickbold or Martin-Floret burner (ASTM D-2784, IP 243). 

A more recent development is the Wickbold method (ASTM D-2785, IP 243). This is basically similar to the lamp method except that the sample is burned in an oxy-hydrogen burner to give much more rapid combustion. An alternative technique, which has the advantage of being nondestructive, is X-ray spectrography (ASTM D-2622). 

Flame Decomposition. Utilization of a petroleum sample as a fuel for combustion in a specially devised burner system, such as that described by Wickbold (6), can be an effective way to destroy large amounts of an organic matrix. The method is applicable to those elements which are either volatile or form volatile compounds and which can be trapped quantitatively in a suitable scrubber. This technique was used to prepare samples for cold vapor atomic absorption determination of mercury. Details are included in Chapter 12. 

Except neutron activation, methods which have been used to determine mercury in organic materials involve a matrix decomposition step prior to the actual measurement. Oxidative techniques involving various combinations of acids and salts have been widely used for matrix destruction (1, 2, 3, 4, 5), as have the Schoniger, Wickbold, and other bomb and tube combustion techniques (1, 6, 7, 8, 9,10). 

The Project investigated two methods for sample decomposition before mercury measurement. One involved acidic oxidation, and the other involved combustion in a Wickbold oxy-hydrogen burner (26). 

Adjust the oxygen regulator on the Wickbold apparatus to 9 psi and the hydrogen regulator to 3 psi. Immediately light die burner with the induction coil and attach the combustion chamber to the burner. 

Shut down the Wickbold apparatus by turning off the nitrogen, hydrogen, and oxygen in this order. Remove the absorber. Wash the spray trap and the cool combustion chamber with a stream of water into the absorber. 

The first fluoride instrument design employed catch and hold valves which served to capture and concentrate the combustion products prior to detection. The results achieved with this oxygen combustion/ISE method were compared with the commonly used Wickbold method. It was shown that the results corroborated and, furthermore, the relative standard deviations were decreased with the oxygen combustion/ISE method (see Table 1). 

The oxidative combustion wifli ion-selective electrode method described here can be used to accurately determine fluorine in liquid hydrocarbons and liquefied petroleum gases at levels down to 0.5 ng/pl. Results obtained are in good agreement with those achieved with the Wickbold Oxy-Hydrogen Combustion method. The oxidative combustion with ion-selective electrode method is less time consuming, less hazardous, and more sensitive than the Wickbold method. The analysis is also applicable to a range of sample types not discussed here, including aqueous based systems and solids. 

Fig. 118. Wickbold apparatus, type 5 SB) = Suction burner C) = Combustion chamber with H2 O2 flame followed by condenser D) = Absorption receiver for washing out gases H) = Stopcock to round flask for condensate S) = Feed stopcock for absorption liquid and rinsing liquid ...

An improved procedure has been described for atmospheric-pressure combustion of samples from high-purity metals [74]. High-pressure digestion with nitric and hydrofluoric acids 75], [76] and combustion techniques have both been shown to be suitable for the decomposition of samples of silicate-containing materials and fuels. Combustion in this case is carried out either in a stream of oxygen [77] or, to provide a closed system, in an oxygen bomb [78]. Mercury can be satisfactorily determined after prior Wickbold ashing [79]. 

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