Elution patterns column

Figure 6.3 shows a comparison of elution patterns of standard polystyrene between a linear-type column and a standard-type column. Because of the high linearity of its calibration curve, the linear series has improved the efficiency of oligomer domain separation. 

Describe the expected elution pattern for a mixture of aspartate, histidine, isoleucine, valine, and arginine on a column of Dowex-50. 

Partition column chromatography for separating several of the primary constituents of the pyrethrum extract has been reported. The elution pattern for some of the constituents of the pyrethrum mixture recovered from the partition column is shown in Table I. 

Adsorption column chromatography has been employed to separate the constituents of pyrethrum. Florisil and aluminum oxide have been used as adsorption columns to retain much of the pigmented materials. The pyrethroids may be caused to elute with several solvents. In our experience mixtures of hexane with ethyl acetate, methanol, ethyl ether, dichloromethane, or acetone have provided different elution patterns. 

The HPLC elution pattern is affected to some extent by the pH of the mobile phase. Moderate pH adjustment to optimize the resolution between EMA and MEMA may be performed. Retention time can be affected greatly by the history of the HPLC column and also the buffer/methanol ratio. The mobile phase ratio should be adjusted to provide adequate separation and retention. Control and fortified samples should be run in the same analytical set with treated samples. 

To study the effect of the protease treatment cell-free suspension, with or without protease treatment, was subjected to gel-filtration chromatography on Sephadex G-75 and the elution patterns were compared (Fig. 1). In each case, two major peaks were detected by monitoring column fractions with absorbance at 280 nm. Degradation activities on mexacarbate, in the presence of FMN and light under anaerobic condition, were measured for each fraction. It was found that the highest activity was associated with peak II. It is interesting to note that protein (s) associated with peak II were detected with or without protease treatment these will be referred to as natural flavoprotein (B, Fig. 

Our first attempt was the feeding of commercially available [guanido-l C]-L-arginine to the cultures of Gonyaulax tamarensis (Ipswich strain). The toxin fraction was isolated and further fractionated to the pure toxins (7). Figure 1 shows an example of the elution pattern of the toxins from a Bio-Rex 70 column. A good correlation between the toxicity and radioactivity was observed. 

Figure 1. Elution pattern of toxins from Bio-Rex 70 column in C-labeled arginine feeding. (Fr. fraction number cpm counts per minute and MU mouse units)...

Fig. 1. —Elution Pattern of Material Precipitated by Ethanol from the Mild-Acid Hydrolyzate of Acacia elata Gum. [Bio-Gel P-300, 90 x 1.5 cm column, M sodium chloride as the eluant flow rate, 3 ml/hr sample, 2 mg in 1 ml of M sodium chloride.]...

The elution pattern in IEC results from the charge distribution on the folded chain. Therefore, IEC was used for indication, whether the native structure of the protein had been affected by previous RPC or not. Ribonuclease was found to retain its native structure, whereas bovine serum albumin, horse radish peroxidase, and ovalbumin were much altered through RPC on a C 18 column with a gradient water/ (ethanol-butanol 80 20) containing 0.012 M HC1 in both eluent components 59>. 

Fig. 12. Diagram of elution pattern of red cell acid phosphatase and various markers on Biogel P 60. The position of the various protein markers was determined both by optical density determination and by starch gel electrophoresis of the individual fractions (83). The experiment was carried out using a polyacrylamide gel (Biogel P 60, 50-150 mesh exclusion limit >60,000 Bio-Rad Laboratories, California) in 0.05 M tris buffer, pH 8.0, containing 0.08% (v/v) Tween 80 and 0.1% (v/v) 2-mercaptoethanol to stabilize the enzyme. Column 60 X 4 cm. Flow rate 20 ml/hr, 4 ml fractions. (A) OD at 280 nm, ( ) OD at 540 nm, ( ) LDH assay with p-nitrophenyl phosphate for AcP. From Hopkinson and Harris (85).

The RP-HPLC system was tested on the fractionation of OPPs and OCPs, from edible fats and oils of both animal and vegetal origin. When acetonitrile was used, the most polar OPPs eluted rapidly but tailed on this column, whereas the relatively nonpolar OCPs were retained the longest. Additional cleanup on miniature Florisil columns is required for the dirtier samples. A UV detector was used to determine the elution patterns of standards (78). The same system was used for the fractionation of OPP residues in processed bay foods prior to the final determination by GC without further cleanup but using a MS detector (66). 

Fractionation and Purification of Ex-1 Cellulase Component from Driselase. Driselase powder (50g) was extracted with several aliquots of water and the precipitate formed upon salting out with ammonium sulfate (on a saturation between 20% and 80%) was fractionated on a DEAE-Sephadex A-50 column. Each fraction was tested for -glucosi-dase, xylanase, CMCase, Avicelase activities, and protein content. The elution patterns are shown in Figures 1 and 2. 

The E-3 peak was high in Avicelase activity and in protein content as compared with CMCase activity. This peak was further fractionated on a Bio-gel P-100 column five protein peaks (E-3-1 to E-3-5) were obtained, of which E-3-2 peak was highest among them in Avicelase activity and protein content. The elution patterns are shown in Figure 3, and the time course of hydrolysis of CMC by these cellulase fractions measured by a decrease in the viscosity is shown in Figure 4. Randomness of them is in the order of E-3-5 < E-3-2 < E-3-1 E-3-4 E-3-3. The E-3-2 fraction was subjected to further purification on a CM-Sephadex C-50 column because E-3-5 was very low in the Avicelase activity. 

Figure 1. Elution patterns of the ammonium sulfate-precipitated enzyme preparation from a DEAE-Sephadex A-50 column. (0) CMC-saccharifying activity (5-min incubation) of eluates diluted 60-fold, (O) Avicel-saccharifying activity (1-hr incubation), ( ) protein concentration measured in terms of the absorbance at 280 nm column 5.0 X 50 cm flow rate 20 mL/8 min one fraction 20 mL.

Figure 2. Elution pattern from Bio-Sil A column of monosialogangliosides prepared from chicken pectoral muscle. Column was eluted with C M HtO (130 70 12, v/v) and changed to C M HtO (120 70 14, v/v) at the arrow.

Elution Patterns for Pesticides in Florisil Column Cleanup Table 2.20.3... 

In alumina column cleanup, the column is first preeluted with ether-pentane mixture (30 70) before the sample extract is transferred onto the column. It is then successively eluted with ether-pentane mixture of 30 70 and 50 50% composition, respectively. This separates A-nitrosodiphenylamine. The latter elutes into the first fraction, from the interfering substance diphenylamine which goes into the second fraction along with the analytes A-nitrosodimethylaminc and A-nitrosodi-n-propy lamine. A small amount of the latter compound is also eluted into the first fraction. A cleanup procedure for other nitrosamines (not classified under U.S. EPA s priority pollutants) should generally be the same as described above. The composition of ether-pentane mixture and the elution pattern, however, must be established first before performing the cleanup. 

Elution pattern 1,3-isomer followed by 1,4- and then 1,2-isomer, on a fused silica capillary column, e.g., VOCOL. 

Figure 4. Elution patterns for rabbit antisera samples from a lactosyl sepharose column A = preimmune serum, B = anti-S -faecalis serum, C = anti-Gal-BSA serum and D — anti-Lac-BSA serum...

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