To begin, the Ocean Optics UV/Vis spectrometer was connected to a laptop using the GoLink!, and then logger pro was opened to record the data. Next, the spectrometer was calibrated using a 1cm acrylic cuvette cleaned with deionized water. The cuvette was then filled with deionized water and placed into the sample chamber of the spectrometer. Experiment_Calibrate_Spectrometer: 1 was selected and then 6o seconds passed while the lamp in the spectrometer warmed up. Once the lamp was fully warm, the calibration was finished. The optically clear sides of the cuvette were not touched since that is where the light shines through. The green apple Gatorade was poured into the cuvette carefully, and the absorbance was measured by the spectrometer. The …show more content…
The concentrations of blue-1 and yellow-5 food dyes were taken from the labels in their stock containers. The equations C1*V1=C3*VVF and C2*V2=C4*Vvf were used to determine the volumes needed for the final solution and Vvf-V1-V2= the amount of deionized water needed. Two burets were cleaned with deionized water and then filled with each food dye to the maximum measured amount the burets could hold. Then, the burets transferred the amount of each dye needed to the final solution to recreate the concentration found in the green apple Gatorade. Deionized water was added with a clean 5 mL pipet and small pipet till the solution was leveled with the mark. The solution was then mixed well together and transferred into the clean 1 cm cuvette, which was placed into the spectrometer to determine if the solution matched the final concentration. The wavelength and absorbance of the two peaks were recorded and compared to the data recorded from the green apple Gatorade measured previously (λ3 A3 and λ4 A4 with λ1 A1 and λ2 A2). The percent error of the two absorbance values were calculated using the equations, %=A3-A1/A1 and %=A4-A2/A2. The percent’s calculate showed the accuracy of the
Data from Table 1. confirms the theory that as the concentration of glucose increases so will the absorbance of the solution when examined with the glucose oxidase/horseradish peroxidase assay. Glucose within the context of this assay is determined by the amount of ferricyanide, determined by absornace, which is produced in a one to one ratio.1 Furthermore when examining the glucose standards, a linear calibration curve was able to be produced (shown as Figure 1). Noted the R2 value of the y = 1.808x - 0.0125 trend line is 0.9958, which is statistically considered linear. From this calibration curve the absorbance values of unknowns samples can be compared, and the correlated glucose concentration can then be approximated.
The essential points of the green-frosting are the concentration and absorbance value in each diluted which the process of serial dilution. The standard curve of Blue#1 and yellow #5 provide the equation of the trend-line in order to calculate the concentration in the diluted solution of the green frosting. The mole of dye in 100mL green stock solution, mole of dye in 5 gram and 1 gram of frosting, the Beer –Lambert Law, and the compare to amount desired by the company can be determined. The Beer-Lambert Law is the relationship between color and the concentration and equation A=Ebc. The “A” is absorbance, the “C” is a concentration in molarity, the “E” is a molar absorptivity and “b” is the path-length. The goal of the lab is to use the absorbance and the Beer-Lambert law to determine the amounts of blue#1 and yellow #5 in the green frosting.
The unknown bacterium that was handed out by the professor labeled “E19” was an irregular and raised shaped bacteria with a smooth texture and it had a white creamy color. The slant growth pattern was filiform and there was a turbid growth in the broth. After all the tests were complete and the results were compared the unknown bacterium was defined as Shigella sonnei. The results that narrowed it down the most were the gram stain, the lactose fermentation test, the citrate utilization test and the indole test. The results for each of the tests performed are listed in Table 1.1 below.
Compress the safety bulb, hold it firmly against the end of the pipette. Then release the bulb and allow it to draw the liquid into the pipette.
The independent variable for this experiment is the enzyme concentration, and the range chosen is from 1% to 5% with the measurements of 1, 2, 4, and 5%. The dependant variable to be measured is the absorbance of the absorbance of the solution within a colorimeter, Equipments: Iodine solution: used to test for present of starch - Amylase solution - 1% starch solution - 1 pipette - 3 syringes - 8 test tubes – Stop clock - Water bath at 37oc - Distilled water- colorimeter Method: = == ==
... samples before the incubation of 108 seconds. Then the 100 µL of colour reagent was put to the sample, merged and incubated for further 10 minutes. The absorbance at 615nm and 700nm wavelengths was calculated on the samples in the Cobas analyser and the sample concentration was measure according to :
The basic principle of the spectrophotometeric technique is the measurement of interaction between energy and electrons of the substance. Spectrophotometric technique is an analytical method used for estimating concentration of metal ion in liquid solution. One of the most magnificent effects of complex formation is the change of spectral properties. The reason for light absorption by complexes are as follows.
The Effect of Temperature Change on Photosynthesis Serena Kim Lucia Yu McGill University Introduction What is photosynthesis? Photosynthesis is a process that is responsible for present life in the planet because it supplies food and energy source for all living organisms. In addition, plants produce oxygen by photosynthesis, the gas that is essential for our life.
the water baths I think were accurate enough but having two thermometers in each bath maybe would have helped to hold the temperature readings more accurately. We were not given any instructions either to shake or not to shake the test tubes with the coloured solutions before inserting them in the spectrophotometer to read the absorbance. By shaking each test tube a certain number of times before putting it in the spectrophotometer could have improved the accuracy of the absorbance of the solutions.
The same procedure was done using 10ml of CV and 20ml of sodium hydroxide, both separately diluted to 50ml and added in a large beaker. The absorbance was recorded. In the last trial, 10ml of CV, 10ml of NaOH were diluted to 50ml. Before adding the two mixtures, 1ml of soap was added to the NaOH solution and then poured into a large beaker, along with the CV. Absorbance was recorded and the materials
Measure the mass of calcium hypochlorite before freshly inserting it into the pool of water using a weight balance Concentration of sodium thiosulfate (0.01 M) If the concentration of sodium thiosulfate differs for each trial, the different concentrations may manipulate how much volume of the solution is used up to produce the change in color when it is titrated with hypochlorite and potassium iodate. Use the right sodium thiosulfate with the intended concentration and do not dilute or mix up the solution with other solutions during the experiment Concentration of potassium iodate (1 M) If the concentration of potassium iodate differs for each trial, the different concentrations may manipulate how fast the change in color would appear in Erlenmeyer flask when it is titrated against sodium thiosulfate Use the right potassium iodate with the intended concentration and do not dilute the solution with other chemical solutions during the
This experiment sought to determine how much food dye was in each color of PowerAde, this was done with the use of a spectrometer to measure absorbency and concentration of the dyes in the drinks. Three colors of dyes were tested in the spectrometer to identify the maximum absorbency wavelength of each. Figure one shows the max absorbency and concentration for each color of dye. For each of the dyes the light transmitted was the color of the food dye that was seen however the absorbed color was its complimentary color. For example yellow was the color transmitted however blue was the color absorbed, red was the color transmitted and green was the color absorbed and blue was the color transmitted and orange was the color absorbed. The second
This experiment demonstrated the ability of agarose gel electrophoresis to separate the mixture of dyes into their individual components by the application of a combination of dyes to the same sample well. The experiment effectively demonstrated that the dyes where different in structure, energy, and composition. Most of the dyes where negatively charged at neutral pHs and only one with positive charge. The positive charge one moved an opposite direction compared to the other dyes.
It changes from blue to red with acids but loses its colour in the presence of certain chemicals, one of which is vitamin C. DCPIP solution can be used to test for the presence of vitamin C in foods. Hypothesis Orange juice has the highest content of vitamin C. Citrus fruits have a higher content of vitamin C. The orange and lemon juice contain more vitamin C than the pineapple juice. Furthermore, as lemons are more acidic than oranges, I predict that the orange juice will contain more vitamin C than the lemon juice. Vitamin C affects, the ph the more vitamin C the higher the ph. Variables Independent Variables Different fruit juices (Pineapple, orange and lemon).
Next, after all the disk sunk completely, the solution was transferred evenly ( 10 disks in each cup). One cup was placed under a light source and one cup covered by a paper towel. Once the cup was placed under the light source a timer was turned on, set to one minute. The two cups were observed after every minute for 15