Column florisil

Carbaryl, carbofuran Column (Florisil, alumina, activated carbon) Apples, potatoes, sugarbccts GC 13... 

Carbamates Column (Florisil) Com, potatoes, wheat HPLC 51... 

Partition, column (Florisil) Wheat and vegetables HPLC 34... 

Transfer the supernatant through a florisil/carbon column. Florisil/carbon column is prepared by adding 3 g carbon (Supelclean Envi. carb, 120/400 from Supelco, SO g bottles are available) and 3 g florisil (JT baker, 60-100 mesh). Florisil is activated at 675 deg C prior to use. Use PP columns, not glass columns. 

A solution of about 300 mg of 25-hydroxyprecholecalciferol prepared as described above in 5 ml of chloroform is heated for 3% hours at 70°-75°C under Nj in a sealed flask. The solvent is evaporated and the residue is chromatographed through a 60 g column containing TLC grade Florisil, 150-200 mesh packed wet with 35% ethyl acetate in Skellysolve B hex-... 

Alternatively, as described in U.S. Patent 3,341,557, 6-dehydro-17-methyltestosterone may be used as the starting material. A mixture of 0.4 g of cuprous chloride, 20 ml of 4 M methylmagnesium bromide in ether and 60 ml of redistilled tetrahydrofuran was stirred and cooled in an ice bath during the addition of a mixture of 2.0 g of 6-dehydro-l 7-methyl-testosterone, 60 ml of redistilled tetrahydrofuran and 0.2 g of cuprous chloride. The ice bath was removed and stirring was continued for four hours. Ice and water were then carefully added, the solution acidified with 3N hydrochloric acid and extracted several times with ether. The combined ether extracts were washed with a brine-sodium carbonate solution, brine and then dried over anhydrous magnesium sulfate, filtered and then poured over a 75-g column of magnesium silicate (Florisil) packed wet with hexanes (Skellysolve B). The column was eluted with 250 ml of hexanes, 0.5 liter of 2% acetone, two liters of 4% acetone and 3.5 liters of 6% acetone in hexanes. 

The residue was redissolved in methylene chloride and chromatographed over 500 g of Florisil anhydrous magnesium silicate. The column was eluted with 1 liter portions of hexanes (Skelly-solve B) containing increasing proportions of acetone. There was so eluted 6a-fIuoro-9/3,1113-epoxy-16a-methy 1-17a,21 -d I hydroxy-1, 4-pregnad ene-3,20-dione-21-acetate which was freed of solvent by evaporation of the eluates. 

The mycelium (56 g dry weight) was filtered off and the steroidal material was extracted with methylene chloride, the methylene extracts evaporated to dryness, and the resulting residue chromatographed over a Florisil column. The column was packed with 200 g of Florisil and was developed with five 400-ml fractions each of methylene chloride, Skelly-solve 8-acetone mixtures of 9 1, 8 2, 7 3, 1 1, and methanol. The fraction eluted with Skellysolve 8-acetone (7 3) weighed 1.545 g and on recrystallization from acetone gave, in three crops, 928 mg of product of MP 210° to 235°C. The sample prepared for analysis melted at 245° to 247°C. 

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 primary method for detecting methyl parathion and metabolites in biological tissues is gas chromatography (GC) coupled with electron capture (BCD), flame photometric (FPD), or flame ionization detection (FID). Sample preparation for methyl parathion analysis routinely involves extraction with an organic solvent (e g., acetone or benzene), centrifugation, concentration, and re suspension in a suitable solvent prior to GC analysis. For low concentrations of methyl parathion, further cleanup procedures, such as column chromatography on silica gel or Florisil are required. 

GC/ECD or a halogen-specific detector (HSD) (Method 8080) is the technique recommended by EPA s Office of Solid Waste and Emergency Response for determining a- and [3-endosulfan and endosulfan sulfate in water and waste water at low-ppb levels (EPA 1986a). At these low concentrations, identification of endosulfan residues can be hampered by the presence of a variety of other pesticides. Consequently, sample clean-up on a Florisil column is usually required prior to analysis (EPA 1986a). 

Up on Florisil column and an elemental sulfur removal procedure are used to reduce or eliminate interferences. Sensitivity is in the sub-ppb range. Recoveries and precision are good. 

Municipal and industrial discharge Extraction of sample with methylene ohloride water removal exchange to hexane volume reduotion olean-up on Florisil column and removal of elemental sulfur GC/ECD GC/MS 0.014 pg/L ( "endo-sulfan) 0.004 pg/L ( "endosulfan) 0.066 pg/L (endosulfan sulfate) 97 ( "endosulfan) 93 ( "endosulfan) 89 (endosulfan sulfate) EPA 1991b (Method 608)... 

Sediment soil Extract of sample with methylene chloride acetone (1 1) clean-up extract using Florisil column GC/ECD 0.002 pg/g (ppm) ( "endosulfan) 0.004 pg/g ( "endo-sulfan) 0.004 pg/g (endosulfan sulfate) No data Marsden et al. 1986... 

Fruits vegetables Homogenization of sample with acetonitrile and clean-up on Florisil column GC/ECD <1 ppm (mg/kg) 101.5B103.6 ( endosulfan) 100B102 ( endosulfan) 92.9 (endosulfan sulfate) Mitchell 1976... 

The residue of the acetonitrile extract described above is dissolved in 5 mL of n-hexane and applied to a silica cartridge. Naproanilide and its metabolite are eluted with 10 mL of n-hexane-diethyl ether-acetic acid (85 15 1, v/v/v) after washing the cartridge with 5mL of n-hexane-diethyl ether-acetic acid (95 5 1, v/v/v). When using a Florisil column (10-g), naproanilide is eluted with 100 mL of diethyl ether-n-hexane (1 1, v/v) after washing the Florisil column with 100 mL of diethyl ether-n-hexane... 

Propanil and its metabolite in the n-hexane phase of the soil extract derived from Section 3.2.2(2) are passed through a Florisil column (previously activated at 300 °C overnight and deactivated with 2% water 2 g). Propanil residues are eluted with 20 mL of diethyl ether-n-hexane (1 1, v/v). 

A homogenized sample of cereals, vegetables, fruits or potatoes (10-20 g) is extracted with an organic solvent such as acetone and methanol. After filtration, the extract is concentrated to about 20 mL by rotary evaporation below 40 °C. The residue is transferred with 5% sodium chloride (NaCl) aqueous solution and partitioned twice with n-hexane. The n-hexane extracts are dried with anhydrous sodium sulfate and subjected to a Florisil column chromatographic cleanup procedure. The eluate from the Horisil column is concentrated to dryness and the residue is dissolved in an appropriate amount of acetone for analysis by GC/NPD. ... 

Residual dinitroaniline herbicides are generally extracted from 10-25 g of air-dried soil samples using organic solvents such as ethyl acetate, acetonitrile, methylene chloride and acetone by sonication, mechanical shaking or Soxhlet extraction. If necessary, the extract is then cleaned by a Florisil column or SPE. The extract is allowed to evaporate completely to dryness and the residue is dissolved in an appropriate volume of the solvent for GC or HPLC analysis. 

For the determination of five herbicides (ethalfluralin, trifluralin, dinitramine, bu-tralin, and pendimethalin) at fortitication levels between 0.1 and 1 mg soil was extracted with ethyl acetate and the extract was purified on a Florisil column. The residues were eluted with acetone and then analyzed by GC. The average recoveries varied from 75 to 111% for GC/NPD and from 88 to 98% for GC/ITD with the LOD being 0.01 mg kg for both GC/NPD and GC/ITD. The recoveries of pendimethalin at fortification levels ranging from 0.2 to 1 mg kg determined by GC/NPD were between 96 and 101% and the LOD was lower than 0.01 mg kg ... 

In place of silica gel, Florisil is also used as the adsorbent in column chromatography. Purification of chlornitrofen using a Florisil column is as follows after installing a column packed with 10 g of Florisil suspended in n-hexane, the sample solution is added continuously to the column and the initial eluate is discarded. A 100-mL volume of diethyl ether-n-hexane (1 19, v/v) is charged to the Horisil column and the eluate is discarded. Chlornitrofen is eluted with 30 mL of this mixture and the eluate is concentrated to dryness before the addition of acetone for GC analysis. ... 

Examination of the elution solvent from the Florisil column to purify bifenox and chlomethoxyfen was carried out. Bifenox is eluted with 100 mL of acetone-n-hexane (1 9, v/v) after discarding 100 mL of diethyl ether-n-hexane (3 7, v/v) eluate, and chlometoxyfen is also eluted with 100 mL of acetone-n-hexane (5 95, v/v) after discarding 100 mL of n-hexane eluate. ... 

C and dried under a gentle stream of pure nitrogen. The residue is dissolved in 5mL of n-hexane and loaded on the column suspended with 10 g of Florisil in an adequate volume of n-hexane with ca 10 g of anhydrous Na2S04 on the top of the Florisil. An additional 5 mL of n-hexane are transferred to the column, which is drained. Chlornitrofen is eluted with 70 mL of diethyl ether-n-hexane (3 17, v/v). The eluate is concentrated to about 1 mL under vacuum below 40 °C, dried under a gentle stream of pure nitrogen and dissolved in an appropriate amount of n-hexane for GC/ECD. 

Florisil column chromatography is effective in eliminating interfering substances in soil. The organic solvent extracts from soil samples are charged to a column plugged with Florisil which has been activated at 130 °C overnight before use. The effluents from the column with a mixed solvent such as n-hexane-acetone are concentrated to... 

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