Introduction to Laboratory Work - Food Chemistry | FOS 4311, Lab Reports of Food science

Download Introduction to Laboratory Work - Food Chemistry | FOS 4311 and more Lab Reports Food science in PDF only on Docsity! Laboratory 1 Introduction to laboratory work 1.1. Rules and regulations 1.1.1 No contact lenses. This rule is for your benefit as any chemicals that land on an eye with a contact lens will get behind the lens and can cause more damage than on eye alone. Solvent vapors can be taken up by contact lenses and cause damage in absence of a spill. 1.1.2 Wear eye protection. We have groovy shades that should be worn at all times. Each person will get their own set. Wash em, keep em clean and wear them. If you wear prescription glasses you do not need to wear these glasses. However, safety goggles with side protection must be worn where organic solvents or highly corrosive chemicals will be used. 1.1.3 Wear a lab coat. This is to protect you from chemical burns should you or your labmates spill acids or base or other chemicals. Besides, lab coats look cool. Cruise down to the VA before lab and play doctor. 1.1.4 Be careful and clean. If you should spill something wipe it up. There are neutralization solutions for spilled acid and base that should be used before cleaning up acid or base spills. Wipe up your lab bench after working. Points will be deducted on labs for leaving a bench messy. 1.1.5 Know what you are doing. It is required that you have read the lab procedures before coming to lab. You will be observed by the instructors and TA’s in the lab throughout the term and may be asked to explain some of the procedures you will perform. Your preparation and knowledge in the lab may contribute to your grade. 1.1.6 Know what to do in case of fire, chemical spill or getting something in your eye. If you spill something on yourself, go immediately to the sink and wash it off. Know how to use a fire extinguisher and what fire types the extinguishers available in the lab are good for. Know where the eyewash fountain is and how to use it. 1.1.7 Read the lab safety manual on the door. I have copies that can be borrowed for one day to read. Copies of the MSDS data sheets for chemicals that will be used will be available in Dr. Kristinsson’s lab or in our lab. By law you must understand the chemical nature and dangers of the chemicals that we will be using in the lab. 1.1.8 No mouth pipetting. Ever. 1.1.9 No food or drink in lab. If you are really cool and smoke, it is a really dumb idea to indulge your addiction in any laboratory where highly flammable solvents and gasses are present. Did you ever notice that organic chemists who smoke in lab don't have eyebrows. 1.2. Operation of analytical balances The analytical balances are extremely sensitive balances that require special handling and operation to use without damaging them. The average replacement cost of these balances is around 3000.00 so understanding how to use them correctly is important. 1.2.1 General rules: ! Always use a beaker or weighing paper. Never place chemicals on the pan directly. 1 ! Be sure the beam is secured (knob up) when placing or removing objects on the pan. ! Release the beam gently. The weighing relies on a precision synthetic sapphire knife edge which is dulled by banging the beam down. ! Close the door when recording weights. ! Leave the balance clean. 1.2.2 Procedure for weighing with Mettler single pan balances. (from Quantitative Organic Chemistry, Fritz and Schenk, 1979; Allyn & Bacon). ! Know where the following knobs are located and their function: beam control, zero, 0.1 g, 1 g, 10 g. ! The beam control is the large knob on the left of the green balances and front of the gray. There are three positions: secured : straight up semirelease : forward (right on gray) full release : back (left on gray) i. Zero the balance by making sure nothing is on the pan with both doors closed. Turn the knob carefully to full release. Adjust the zero knob on the right side of the balance so the reading is exactly 0.000. Be sure you know how to read 4 decimal places from the scale. ii. Move the knob back to secure. Familiarize yourself with the 3 knobs controlling the weights. iii. Weigh the object in the following manner. Place your object to be weighed onto the pan making certain that the beam control is set to secured. Close the side windows and place the beam control in the semi release position. Adjust the weight knobs until the weight is known to the nearest 0.1 g. Completely release the beam and read weight from the optical scale. Before removing the object set the beam control to secured. Set the weight setting knobs to zero, clean the pan if necessary and close the side windows. 1.3. Operation of pipettors We have a number of pipettors that can be used to measure small volumes of liquids. They must be used properly and treated carefully or they will be ruined. Watch the demonstration and take special note of how to fill them, empty them, dispose of used tips and care for them. 1.4. General lab procedures You will be shown examples of how to properly fill burets, glass pipettes, and other liquid measuring glassware. Handling acids, bases, toxic and flammable solvents will be discussed. Proper operation of a Waring Blender will be demonstrated. 1.5. Lab reports: format You should maintain a lab notebook to keep up-to-date records, modifications of procedures, calculations, graphics, etc. A ballpoint pen with black or blue ink is acceptable. Any other color pen will not be acceptable. This is part of your participation grade. Lab reports and graphs must be typed and they must be submitted according to the schedule in your syllabus and on page 5 above. 2 Lab reports (from syllabus) will consist of the following: 5 Format for Writing Laboratory Reports I. Names of the lab group members with signatures II. Title of Lab 2 Point III. Introduction which includes Purpose and Objective 3 Points IV. Procedures Cite laboratory book as a reference Changes (list any changes from lab handout) 3 Points V. Results Tabulate results, show sample calculations; Graph data (data will be in QuatroPro); Do statistical analysis where possible. 8 Points VI. Discussion & Conclusions Discuss the results, what their implications are and how they may relate to real life. Note: To get a 10 out of 10 you will need to go to the library and look up additional information on the subject and incorporate the information into your discussion. Be sure to cite the information and reference it. Appropriate library information includes books (excluding text, reference books, etc.), journal articles, etc. 10 Points VII. References (examples will be given) Total 4 Points 30 Points 6