Wickbold apparatus

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),... 

Application to Acidic Permanganate Absorber. In the Wickbold apparatus the mercury is collected in the acidic permanganate absorber. In this case, a solution of hydroxylamine must be added to the absorber prior to measurement to reduce all the manganese to the divalent state, in which form it does not interfere with the reduction of ionic mercury to elementary mercury by tin (II). 

Scope. This method is applicable to the determination of mercury in petroleum and petroleum products (except leaded gasoline) which can be burned in a Wickbold apparatus. The method is capable of measuring the amount of mercury in a sample down to the 5-ng/g level. The upper limit of the method as presented is determined by the linearity of the mercury calibration curve (Figure 1.2). Three to four samples can be analyzed conveniently at one time, and the average analysis time is about 2 hr. 

Weigh 20 g of oil into a 250-ml beaker and add 40 ml of benzene and 10 ml of 2-propanol. Dissolve the sample completely, then transfer the oil solution quantitatively into the sample reservoir of the Wickbold apparatus. This procedure is for samples estimated to contain 5-150 ng/g of mercury. Smaller samples can be taken if higher amounts of mercury are present. 

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. 

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 ...

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

Wickbold Decomposition. The Wickbold decomposition apparatus is shown schematically in Figure 12.2. It consists of a sample reservoir, stainless steel burner, quartz combustion chamber, and an absorber con-... 

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. 

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). 

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

Fig. 121. 1-litre apparatus for suriactant concentration by blowing out, after Wickbold (Dimensions in mm) 1) = Ethyl acetate 2) = Water sample 3) = Glass filter frit... 

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

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