Filtration analysis

This equation is the basis of cake filtration analysis. Feed Hquid flow rate and filtrate volume Dare usually assumed to be related as... 

Figure 7. EDTA-Soluble Polyuronides and Gel Filtration Analysis of EDTA-Soluble Polyuronides Isolated from TA8-23 and TA8-48 Br+7 Fruits.

Dissolve the antibody to be conjugated in 0.1M sodium phosphate, 0.15 M NaCl, pH 7.5, at a concentration of lOmg/ml. If the antibody contains oligomers (as evidenced by nondenaturing electrophoresis or HPLC gel filtration analysis), then the monomeric IgG... 

Gel-filtration analysis reveals bands of molecular mass 40-70 kDa. These represent dimers (and some multimers) of the IFN-y polypeptide. Its biologically active form appears to be a homodimer in which the two subunits are associated in an antiparallel manner. 

Figure 16. Osmotically induced transformations of muta-rotase monitored by membrane filtration analysis...

Honda and Tokushige reinvestigated the effect of temperature and monovalent cations on the quaternary structure of tryptophanase using the HPLC gel-filtration analysis.28 In contrast to the above-mentioned data, they found that in the absence of K+ or NH4+ ions the tetrameric holoenzyme undergoes dissociation into dimers and inactivation at 5°C. Their results also indicate that formation of the active holoenzyme from the apoenzyme and PLP proceeds in two steps the inactive tetrameric species are first formed then converted to the active species only the second step requires the presence of K+ or NH4+ ions (Fig. 9.3)... 

All hydrogenation experiments were carried out at atmospheric pressure in a reactor, consisting of a flask attached to a burette filled with mercury and equipped with stopcocks that permit removal of air before the introduction of hydrogen. The mixed catalyst/solid substrate was placed at the bottom of the flask reactor to form a thin layer (2-3 mm) and then evacuated to approximately 10-3 Torr for 10 min. After introducing hydrogen (760 Torr), the reaction was carried out until complete transformation of the solid had occurred usually the reaction was completed within 18 h. This transformation was accompanied by the formation of thin needles on the surface of the solid catalytic bed, which correspond to the resulting products cA-4-tert-butylcyclohexanol, /ra s-4-/err-butylcyclohexanol and 4-tert-butylcyclohexanone. The reaction mixture was extracted with ethyl ether, and the catalyst separated by simple filtration. Analysis of the products was carried out by gas chromatography and mass spectroscopy. 

Although several previous reports claimed that the enzyme had been purified, Gebler and Poulter (1992) appear to have been the first to fully characterize the activity of the purified DMAT synthase. The enzyme was purified from Claviceps fusiformis ATCC 26245 [erroneously annotated in type specimen collections as a C. purpurea strain (Pazoutova and Tudzynski, 1999)]. The monomeric size was estimated at 53 kDa, and by gel filtration analysis the native enzyme was determined (at 105 kDa) to be a homodimer. Unlike other prenyltransferases, no metal ion requirement has been noted. However, when assayed in a buffer with 4 mM Ca2+, the purified protein gave a specific activity of 500 nmol/min/mg, essentially the same as with 4 mM Mg2+, but approximately twice that of the measured without added divalent cations and with the chelator EDTA included in the assay buffer. These divalent metal cations eliminated negative cooperativity of substrate binding observed both for dimethylallyl diphosphate and L-tryptophan, indicating that Ca2+ and Mg2+ probably had allosteric effects. In buffer with 4 mM MgCl2 the KM for dimethylallyl diphosphate was 8 jlM, and the KM for L-tryptophan was 12 xM. The enzyme product was authenticated by mass spectrometry, UV spectrometry, and -NMR. 

Thermal decomposition of the carbonyl anion was promoted by refluxing the solution 1 hr during this time a dark microcrystalline solid precipitated. The black solid was isolated by filtration and placed in a Soxhlet extractor with 1,2-dichloroethane. After two weeks of continuous extraction, virtually all of the solid had passed through the frit 4.87 grams of recrystallized solid were isolated from the solution in the extraction flask by filtration. Analysis for [(C4H9)4N]2Mo4lioCl calcd Mo 17.66, I 58.40, Cl 1.63, C 17.68, H 3.34, N 1.29 found Mo 17.72, 1 58.25, Cl 1.53, C 18.08, H 3.32, N 1.46. 

Figure 6.36 Complete blocking and cake filtration analysis for the WO kDa membrane at 2.5 mM CaCl, pH 7-8 and 12.5 mgL IHSS HA at stirred (270 rpm) and unstirred conditions.

The surface of each filter element serves as a support for the deposited solids. The real filter medium is the solids themselves. Their aceumulation causes the resistance to flow to increase continuously. This is the distinguishing characteristic of cake filtration. Analysis of the process requires some way to describe the changing relationship between flow rate and pressure drop. Here, we follow the method of Foust and coworkers [113]. 

Tien C., Teoh S.K. and Tan R.B.H., 2001. Cake filtration analysis - the effect of the relationship between the pore liquid pressure and the cake compressive stress, Chem. Eng. Sci., 56, 5361-5369. 

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