In 10 g dried sediment sample added 7 ml 0.2 M NH4Cl solution. A mixture of 100 ml hexane: acetone (1:1) was used as a solvent to extract pesticides with overnight shaking for 12 h on reciprocal or wrist action shaker at 180 rpm. The extract was carefully decanted through activated florisil column (2-3 cm), giving twice wash with25 ml hexane: acetone (1:1) to the sediments. The elute was then washed with 200 ml water and then again aqueous layer was extracted with 50 ml hexane. Finally the hexane layer was washed with 100 ml water and then evaporated to dryness with a vacuum rotary evaporator.
The developing solution was poured into a tank and was tightly covered with a glass lid, and the tank was allowed to be saturated to ensure that the solution was equilibrated in the gas phase. Silica plate for TLC analysis: A horizontal line was drawn with a pencil on the plate and it was about 1 cm above the bottom of the plate. The horizontal line was drawn faintly so as to avoid damaging the silica gel on the plate. On the horizontal line, two marks were made and one was named A and the other B. These marks were made towards the centre of the plate at a distance apart because when spots are made at the edge of a plate, the result would be an improper travel of the samples as the solvent advances on the plate.
TLC was used to identify the actual unknown product as well as other products/reactants present in the filtered solution. The procedure was conducted by placing a TLC plate in a developing chamber that is filled with a small amount of solvent. The solvent cannot be too polar because it will cause spotted compounds on the TLC plate to rise up too fast, while a very non-polar solvent will not allow the spots to move. The polarity of the spots also determines how far it moves on the plate; non-polar spots are higher than polar ones. After spots on the TLC form, the Rf values are calculated and used to analyze the similarity of the compounds.
This was proved by utilizing the IR spectrum to verify the C=O was not in the final product as it lacked the 1640 cm-1 peak. The melting point of 113-115 degrees C proved that the final product obtained was the E-Stilbene. The TLC plate proved that the E and the Z product was produced, show cased by the double intensity of the DCM spot to the final product’s spot, both which had an Rf of 0.92. The double intensity proved that both products were produced, but through heating and filtering, the Z-Stilbene was
Experimental Methods: 1. SYNTHESIS OF 4-BENZOYL BUTYRIC ACID METHYL ESTER Materials required * 5 oxopentanoic acid : 2 gm (Aldrich) * Methanol : 50 ml * Acetic Acid (Rankem) Procedure: * 2 grams of 5 oxopentanoic acid was weighed and placed in a round bottom flask and then to it 50 ml of methanol was added. It was placed on a hot plate and the temperature was increased to 50 degrees under ambient air conditions. * To the RB, 2 ml of acetic acid was added and then by attaching a condenser the entire reaction was put on refluxing at 70 degrees Celsius in an oil bath. * For work up: * The reaction media was concentrated till about 10 ml and then dry silica gel was added.
The developing chamber for the TLC plates was prepared by adding ethyl acetate that contained 0.5% acetic acid to the glass jar. The TLC plates were prepared by drawing a horizontal line from bottom margin (0.5cm) where the four spots were placed. Separate small capillary tubes were used to spot solutions of Tylenol, Anacin, acetaminophen and acetylsalicylic acid respectively on the drawn line. The spotted TLC plate was placed in the developing chamber (glass jar) ensuring the solution in the glass jar is below the drawn line, followed by covering the top of the glass jar(Qui, Haixing, and Yusheng
As well as the ending line, where the solvent stopped. The higher the compounds go up the more polar the substance is. (1) On the TLC that was done in the practical 1 two lines had roughly the same distance of 2.55-2.6cm. The reaction material was higher of about 2.9cm and the final product was lower (1.9cm). This means that the reaction materials had a higher polarity than the other 3.
Summary Determining the concentration of a liquid can be a tricky process involving complex procedures if it were not for science’s ability to test a substance’s absorbency through spectrophotometry. The experiment was carried out to discover the concentration of Red Dye #40 in several common soft drinks. The samples of the dye were diluted, and tested using a spectrophotometer. The absorbencies of these samples were then recorded, and a standard line curve with the concentration equation and R2 value was created with these results. Using the absorbencies of the dye samples, the concentrations of the soda samples were determined using the slope equation provided by the graphing software.
Xylene should be dried because it will be removed from the product. A drying tube with calcium chloride was used for the reaction during the set up because it will remove and catch specific compounds leaving the reaction or being produced from the reaction. The purification method is by using adding petroleum ether to produce crystals and then vacuum filtration to remove the crystals from the solution. The melting point for 4-cyclohexene-cis-1,2-dicarboxylic anhydride as a pure compound is measured at approximately 97-103ºC. The measured melting point from the experiment is approximately 70-80ºC.
• Injection volume: 20μl • Injection concentration: 1mg /ml • Detection wavelength: 280nm 2.3.6-Isolation and purification of Flavonoids (Genistien, Rutin, Quercetin) by: 220.127.116.11- Preparative TLC plate: Isolation and purification of genistein,rutin, quercetin were carried out by preparative TLC. On a glass plates (20 cm x20 cm) a slurry of 60 gm of silica gel GF 254 suspended in 120 ml of distilled water was applied in 0.75 mm thickness manually by using Jobling laboratory division plate coater. The freshly coated plates were left until the transparency of the layer disappears. After 10 minutes, the plates heated for 1 hour at 110ºC. The completely dried and activated plates are kept in a dry place for use.