Premium Essay


In: Science

Submitted By cbg5013
Words 1622
Pages 7
Spectrophotometry is a quantitative analysis that is essential the subject of chemistry. It measures reflection and transmission of various materials as a function of wavelength. This is a relatively basic concept that is often taught in early chemistry courses such as high school chemistries or general chemistry classes. Spectrophotometry uses a number of instruments that each measures a different range of wavelengths. The instrument that our group created was a colorimeter, which can measure wavelengths in the visible light range. This range is approximately 400-700nm. Three experiments were designed to incorporate this instrument; that are relatively low in costs and great for a high school/general level chemistry students. These experiments do not require a great deal of materials and are not for highly skilled chemists.
The basic principles of the physics of color are often taught in high school chemistry and physics classes around the country. Unfortunately, many of these spectrophotometric experiments use harmful solvents to dissolve very small quantities of solute in order to produce a solution with the proper concentration to be analyzed by a colorimeter. Most high schools do not have the ability to dispose of organic waste, and creating a solution of a specific concentration for high school students would likely distract them from the intended task. The proposed colorimetry experiment requires only colored crêpe paper and distilled water in order to prepare solution to analyze. The paper is very inexpensive and the water-soluble dye is non-toxic and can therefore be easily disposed of. Three basic experiments can be run with these materials and the colorimeter we built in lab: the exploration of spectral characteristics of different color solutions, create a calibration curve and explore Beer’s law, and finally explore simultaneous…...

Similar Documents

Free Essay

Introduction for Biochemistry Lab -Spectrophotometry

...Introduction Every chemical compound absorbs, transmit or reflect light over a certain range of wavelength. In this experiment one of the main purpose is to introduce students to the quantitative and qualitative study of spectrophotometry. Spectrometry is the measurement of light that is absorbed or transmitted by the sample solution (Vo, n.d). It is one of the most commonly used methods in various fields to study the quantitative analysis of light that passes through a solution. Meanwhile, the use of spectrophotometer to determine the extent of absorption of wavelengths of visible of light is known as colorimetry. The intensity of light that passes through the sample as well as the concentration of the substance is measured by a spectrophotometer. The instrument consists of some basic components: Radiation light source (tungsten for visible region and deuterium lamp for ultraviolet region), wavelength selector (to isolate a desired wavelength form the source), a cuvette or container to hold the sample solution and a detector (photometer) which delivers the signal in a display device. The voltage output is determined by the difference in the amount of light absorbed by the sample. The fraction of light that passes through the solution is called transmittance, T and the proportion of light absorbed is the absorbance, Abs. Thus, the value of transmittance can be calculated by using the following formula: Transmittance, I = It/ I0 where, It = intensity of...

Words: 716 - Pages: 3

Premium Essay

Oxalate Lab inaccurate filtration), contaminated or already-catalyzed H2O2 (which would result in the hindered oxidation of Fe2+ to Fe3+), and failure to allow the crystals to completely air-dry (mass of H2O would have accidentally been included, resulting in an overestimation of the percentage yield). Part 2 of this experiment invoked the use of redox titrating to determine the oxalate content (C2O42-) of the salt. An aqueous solution of the iron oxalate salt is prepared for titration, and the oxalate content is found through analysis by measuring the volume of titrant. Part 3 of the experiment utilized Spectrophotometry to determine the iron content in the iron (III) oxalate complex. The results were combined with findings from Part 1 and Part 2 to determine the empirical formula and percentage yield of the compound synthesized in Part 1. Spectrophotometry is a routine laboratory test that has the added advantage of being able to analyze multiple samples in a short amount of time. The most efficient way of determining concentration is to prepare a set of standard solutions of known concentration, record the absorbance readings at a fixed wavelength, and plot the absorbance vs. concentration data. The wavelength of 520 nm was selected for experiment Part 3 because this is the maximum absorbance for the iron (III) ion. The Beer's Law Plot that was graphed came out to be linear with an equation of: Absorbance = 5.395 x 10^3(Fe^+2-Bipy) - 0.0014. ...

Words: 607 - Pages: 3

Free Essay

Extraction of Caffeine from Tea Leaves

...different for qualitative analysis. 7. The spectrophotometer (UV-Vis) was used and the absorbance of the light was observed for each solution as quantitative analysis. Then, the graph was gotten 8. The unknown sample’s concentration was found by the graph 3. Introduction and Background The Light of Knowledge is an often used phrase, but it is particularly appropriate in reference to spectroscopy. In Spectrophotometry, a spectrophotometer is used. Basically, this is a device that measures the amount of light that a certain sample absorbs. It operates by passing a beam of light that consists of photons through the sample and measuring the intensity of light reaching a detector. •   Ultraviolet-Visible Spectroscopy: Absorption of this relatively high-energy light causes electronic excitation. The easily accessible part of this region (wavelengths of 200 to 800 nm) shows absorption only if conjugated pi-electron systems are present. A useful analytical tool for determining the concentration of colored material in solution is ultraviolet visible spectrophotometry. Colored substances absorb light in the visible spectrum and the amount of light absorbed is proportional to the concentration of the substance in solution. , where A is the measured absorbance,  is the intensity of the incident light at a given wavelength,  is the transmitted intensity, L the pathlength through the sample, and c the concentration of the absorbing species. For each species and......

Words: 861 - Pages: 4

Free Essay

Identification of Statins in Rice Fermented with Monascus Species from the Museum of Natural History

...available at the Museum of Natural History (MNH) of the University of the Philippines – Los Baños. Specifically, the study aimed: (1) to produce angkak rice using Monascus strains available at the Museum of Natural History (MNH); (2) to extract statins produced in the angkak rice preparations; and (3) to determine the statins produced by the different strains using UV Spectrophotometry. This study served to identify the statins that can be produced by fermentation of rice by Monascus strains available at the Museum of Natural History (MNH), and to identify the strains which are able to produce the higher amounts of statins than do others. This served as a set-off point for further studies regarding the use of fermentation products with regards to treatment of certain ailments, such as heart disease due to abnormal deposition of cholesterol in the body. The research focused on identifying the different statins extracted from the different angkak preparations using different Monascus strains available only at the Museum of Natural History (MNH). Due to budget constraints, screening was done only through UV spectrophotometry; hence, only a crude estimation of the statins was done. METHODOLOGY Monascus Strains A total of eight (8) isolates (Table 1) available at the Museum of Natural History (MNH) of the University of the Philippines–Los Baños (UPLB) were used for the production of angkak rice. Stock cultures were kept in PDA (Potato Dextrose Agar) medium......

Words: 3052 - Pages: 13

Free Essay

Biology Lab

...BIOL2103 Biological Sciences Laboratory Course Practical 3 Laboratory manual Isolation of nucleic acid and spectrophotometry Introduction: The ability to isolate and quantify nucleic acids accurately and rapidly is a prerequisite for many of the methods used in biochemistry and molecular biology. The concentration of DNA or RNA in a sample, and its condition, are often estimated by running the sample on an agarose gel. Such concentration estimates are semiquantitative at best and are time-consuming. For a more accurate determination of the concentration of DNA or RNA in a sample, a UV spectrophotometer is commonly used. Spectrophotometry uses the fact that there is a relationship between the absorption of ultraviolet light by DNA/RNA and its concentration in a sample. The absorption maximum of DNA/RNA is approx 260nm. The purity of a solution of DNA can be determined using a comparison of the optical density values of the solution at various wavelengths. For pure DNA, the observed A260/A280 ratio will be near 1.8. Elevated ratios usually indicate the presence of RNA. The A260/A280 ratio is used to assess RNA purity. An A260/A280 ratio of 1.8-2.1 is indicative of highly purified RNA. The 260/280 ratio below 1.8 often signal the presence of a contaminating protein or phenol. Alternatively, protein or phenol contamination is indicated by 230/260 ratios greater than 0.5. Workflow Time 2 days before the lab session During lab session 1:30......

Words: 842 - Pages: 4

Premium Essay


...At Coast to Coast Flavors, we manufacture and blend flavor concentrates and syrups for the beverage and food service industries.  Coast to Coast Flavors’ customers include Fortune 500 and other large corporations which require strict quality control and manufacturing standards.  We are committed to consistently providing products of the highest quality to all of our customers as well as providing a level of customer service unmatched in our industry.  Our on-site research laboratory supports a state of the art quality assurance platform.  The lab is fully furnished and staffed to complete gas chromatography, spectrophotometry, and microbiological testing in support of both the quality assurance program and our product expansion activities.  Our quality assurance program characteristically includes production-batch testing and sample preservation and can be customized to the special needs of our customers.  The company's laboratory employs full-time staff members to perform quality assurance and product development activities. Ready-2-Use Syrups create a variety of mouthwatering snowball treats for your family, friends or customers. Available in 18 mouthwatering flavors, C2C syrups are easy to use ... simply pour over shaved ice. If more variety is desired, try our IcyOrb brand of concentrates. With 52 available flavors, one for each week of the year, the possibilities are boundless for producing thought-provoking flavor and color combinations. We like to please as many......

Words: 311 - Pages: 2

Free Essay


...2011- Dec 2012 * -Work in the team with the team members and produce all kinds of dough that are required for the factory * -Help package, and label the boxes in the correct order and send them to the warehouse * -Record the time, temperature, weight, and make sure to provide the information to the Quality * Assistant managerAwards-First in the National Essay Competition organized by the Government of Nepal, 2007-Selected to represent Nepal in the 58th International friendship camp in Austria, Vienna organized by Youth Red Cross of Austria, 2009-Selected as the best Youth of Bhaktapur city by Nepal Red Cross Society, Bhaktapur Subchapter-Second in the School wise debate Competition, 2008 and 2009SKills-Electrophoresis, Spectrophotometry, SDS Page, Buffer Preparation, Titration, Pipetting, and other laboratory works-Abilities to keep the lab records accurately-Experience using Microsoft Word, Excel. -Excellent Communication SkillsMembership-Life Long Member of Nepal Red Cross Society-Student Senator, Dickinson State University (2012-2013)-DSU Science Olympiad 2013Reference-Furnished upon request * | |...

Words: 448 - Pages: 2

Free Essay


...high energy chemical molecules that become subunits of carbohydrates. There are four different pigment groups present in leaves of photosynthesizing plants. Studies indicate that only the chlorophyll IS involved in the actual absorption of light energy and later conversion to chemical energy of living cells. The other pigments also absorb light energy, but it is transferred to the chlorophyll for conversion to chemical energy. Biochemists have developed a variety of methods for the purification and analysis of biomolecules. Several of these techniques will be used in this laboratory exercise in order to isolate and study the photosynthetic pigments, chlorophyll a, chlorophyll b, and carotenoids. These include paper chromatography and spectrophotometry. Paper chromatography separates compounds on paper as solvent carries the mixture up (or down) the paper by capillary action. Compounds which are very soluble in the solvent move along with the advancing solvent front, while less soluble compounds travel slowly through the paper, well behind the solvent front. As a result, the different compounds are separated on the basis of their solubilities in the chosen solvent. Chlorophyll a is slightly soluble in a 3:1:1 mixture of petroleum ether, acetone, and water. Carotenoids are very soluble in this solvent system. These solubility differences will allow the separation of chlorophyll a from the carotenoids and chlorophyll b on a paper chromatogram. Having purified chlorophyll a,......

Words: 2526 - Pages: 11

Premium Essay


...these pigments. However when the temperature increases , the permeability of the membrane increases , the molecules gain kinetic energy , lipid molecules become fluid , protein molecules break apart and form holes in the lipid membrane causing the pigments in the innermost compartment to spill out(Mitchel et al. ). In this experiment ,Beet root cells were treated at different temperatures and the effects of temperature on membrane permeability were studied using spectrophotometry. Spectrophotometry was used to quantify the relative amount of betacyanin pigments that leaked out of the beet root cells. These pigments absorb light at a wavelength of 475nm. The amount of light absorbed was proportional to the concentration of the pigments leaked out of the cell. Method We washed a beet root thoroughly and using a cork borer cut it into six cylinders of diameter 1.0 cm. These cylinders were cut to a uniform length of 3.0 cm and then placed in a beaker containing cold running water and rinsed for 5 minutes. A frozen cylinder was thawed and cut to a length of 3.0 cm. Seven large tests tubes were labeled 1-7 and eight small tests tubes (cuvettes) were labeled 1-7 and ‘blank’ One rinsed beet root cylinder was......

Words: 2164 - Pages: 9

Free Essay

Determining Protein Concentration Through Absorption Spectrophotometer in Mice Liver Cells

...each reading. F. Record the measurements in a table G. Take measurements in 5nm intervals at the max. H. Plot all data in excel Materials: References: 1. Duke. (n.d.). Spectrophotometric determination of protein concentration. Retrieved from 2. Hong, W., Wei-Rong, L., Xiao-Feng, G., & Hua-Shan, Z. (2007). Spectrophotometric determination of total protein in serum using a novel near-infrared cyanine dye, 5,5′-dicarboxy-1,1′-disulfobutyl-3,3,3′,3′-tetramethylindotricarbocyanine. Analytical & Bioanalytical Chemistry, 387(8), 2857-2862. doi:10.1007/s00216-007-1153-y 3. Marietta. (n.d.). Measuring protein concentration through absorption spectrophotometry. Retrieved from 4. Sayeed, M., Habib, R., Rahman, M., Banna, H., & Rana, S. (2012). Interaction of Ketotifen Fumarate with Anhydrous Theophylline in Simulated Gastric and Intestinal Media and Effect on Protein Binding. Tropical Journal Of Pharmaceutical Research, 11(2), 263-268....

Words: 735 - Pages: 3

Free Essay

Computer Chips and there are millions of tiny transistors on every computer chip” (University of Copenhagen 2009). I agree with this because as technology advances the equipment gets smaller and smaller. One of the main reasons silicon won’t last very long. But like they say "Silicon is great. It's very hard to beat," said senior author and electrical engineer Subhasish (Meeri, 2013). That is very true. Silicon is very stable and we been able to improve it over time. The challenge will be to try to match it to make it even faster and efficient. Lastly, now for the ways we can introduce how computer simulations comes into play. Bio imaging applications can result in looking for tumors and measurement in pH changes. A great example would be spectrophotometry. We did that in class and it showed us the reading of abundance and molarity. But the most important thing would be that it shows us images of what going on in the system or out body. We can use that to read the scale. “This method combines the strengths of quantum mechanics, molecular mechanics, classical molecular dynamics, and Monte Carlo techniques. Because of this work, it is now possible to perform computer simulation of protein-quantum dot complexes that were previously considered to be beyond the scope of computational investigations” (Syracuse University 2015). Mainly this has shown that in a simulation we can see what’s going on in different perspectives and that is why it can be applied in bigger and complex things.......

Words: 899 - Pages: 4

Premium Essay

Investigating the Effects of Carbohydrates

...7) Charumathi Sabanayagam, Anoop Shankar, Seang Mei Saw, E. Shyong Tai, Su Chi Lim, Jeanette Jen-Mai Lee, and Tien Yin Wong. (2009). Prevalence of Diabetes Mellitus, Glycemic Control, and Associated Factors in a Malay Population in Singapore. Sage Publications. Volume 21 8) Andrew Porteous (2000). Carbohydrates. Hoboken: Wiley. Dictionary of Environmental Science and Technology. 9) Rob Reed, David Holmes, Johnathan Weyers, Allan Jones. (2007). Practical Skills in Biomolecular Sciences. Pearson Education Limited. Third Edition. 10) W. G. Hale, V. A. Saunders, J. P. Margham. (2005). Carbohydrates. London: Collins. Collins Dictionary of Biology 11) Ashraf Essa (2009). Making standard solutions- Introduction to Spectrophotometry. University of Bedfordshire (Luton). BHS006-1....

Words: 1252 - Pages: 6

Premium Essay

Peroxidase in Radishes

...with water. The results proved that the hypothesis was correct; stress on a plant, Vitamin Water in this case, causes higher levels of peroxidase activity. Introduction: Peroxidases are enzymes that use hydrogen peroxide as an electron acceptor to catalyze oxidative reactions. Peroxidase is believed to play a major role in synthesizing cell walls, preventing toxins and responding to stress. It is responsible for the purple color that is seen throughout the experiments. Peroxidase can be found in different locations in a plant in the form of isoenzymes. Many different experiments can be done to locate, visualize and quantify the activity of peroxidase enzymes. These include, tissue printing, dot-blot assays, electrophoresis, and spectrophotometry. This knowledge of what peroxidase does and how its activity levels can be detected was used to develop the hypothesis that the radish that that was watered with Vitamin Water, Plant 2, would be more stressed than the radish that was watered with regular water and that the radish that experienced the most stress to would be the plant that resulted in elevated activity levels of peroxidase. It was hypothesized that this would be seen through a darker color in the tissue prints of the more stressed plant, more peroxidase activity and a higher absorbance in the spectrophotometric assays of the more stressed plant, and more peroxidase isoenzymes in the more stressed plant. Materials and Methods: A radish, a dicot, was selected......

Words: 1307 - Pages: 6

Free Essay

Pei Quantification

...PEI:DNA particles form at a critical PEI:DNA ratio of 0.25 while incorporating all of the available PEI and DNA molecules. At this ratio, the DNA was fully saturated with PEI, and further addition of soluble PEI did not result in incorporation into the nanoparticles. With this assay, a systematic analysis of PEI:DNA complex formation in diVerent standard cell culture media is possible and may help to optimize transfection. References [1] O. Boussif, F. Lezoualc’h, M. Zanta, M. Mergny, D. Scherman, B. Demeneix, J.P. Behr, A versatile vector for gene and oligonucleotide transfer into cells in culture and in vivo: polyethylenimine, Proc. Natl. Acad. Sci. USA 92 (1995) 7297–7301. [2] T. Perrine, W. Landis, Analysis of polyethylenimine by spectrophotometry of its copper chelate, J. Polymer Sci. 5 (1967) 1993–2003. [3] F. Ungaro, G. De Rosa, A. Miro, F. Quaglia, Spectrophotometric determination of polyethylenimine in the presence of an oligonucleotide for the characterization of controlled release formulations, J. Pharmacol. Biomed. Anal. 31 (2003) 143–149. [4] M. Derouazi, P. Girard, F. Van Tilborgh, K. Iglesias, N. Muller, M. Bertschinger, F. Wurm, Serum-free large scale transient transfection of CHO cells, Biotechnol. Bioeng. 87 (2004) 537–545. [5] J. Jeong, S. Song, D. Lim, H. Lee, T. Park, DNA transfection using linear poly(ethylenimine) prepared by controlled acid hydrolysis of poly(2-ethyl-2-oxazoline), J. Control Release 73 (2001) 391–399. Acknowledgment The authors......

Words: 1626 - Pages: 7

Free Essay

Life on Earth

...dioxide is used instead of electricity and ammonia and methane, to make the conditions in the closed chamber more like that of early Earth. - Advances in technology that has increased our knowledge of the origin of life and evolution are the changes in chemical analysis, biochemistry and molecular biology. - Other technological advances: Technology Uses -Microscope which Enabled the discovery or micro-organisms -Radiometric Dating enabled to assign absolute dates to rocks/fossils Has established age of the Earth as 4.5 billion years old -Electron Microscopy which enabled scientists to study minerals, microbes and nature of rocks in detail. Gas and Liquid Chromatography Radioactive Tracing Amino Acid and Nucleotide Sequencing Spectrophotometry Enabled the comparisons between ancient organic material and biological material today • Gather information from secondary sources to describe the experiments of Urey and Miller and use the available evidence to analyse the: _ Reason for the experiment: - To test the hypothesis of Haldane and Oparin - i.e. organic molecules could have been created on the surface of early Earth, from inorganic molecules using energy from UV rays and lightning _ Result for their experiment: - After a week of electrical discharge and recycling steam through their apparatus, they analysed the condensed liquid - It was found to contain amino acids, the building blocks of proteins _ Importance of their experiment in illustrating the......

Words: 1710 - Pages: 7