The Function of a Blank - Assignment Example

The Function of a Blank Please answer the following questions. (Five points each) List four variables that may influence the concentrations of air pollutants. a) source of contaminant b) air flow direction and velocity c) density of the contaminants d) intensity of the sunlight e) time of day f) presence of obstructions such as trees, buildings, machinery, What is the function of a Blank? The function of a blank is to taste any possible effects of other material other than the analyte that is used in the measurement. Usually, the value of the blank if significant is subtracted from the actual reading. It reduces random errors that may be inherent in the use of particular reagents What is isokinetic sampling of particles? Isokinetic sampling is the process of acquiring a sample under such conditions that there is no change in momentum. The process of collecting sample does not in any way affect the prevailing conditions of the surroundings. What is Cryogenic sampling of gases? In cryogenic sampling, the air pollutant is condensed in a cryogenic trap. It is mostly used for volatile organic compounds that are present in low concentrations. Condensation in the cold trap allows preconcentration for easier analysis by GC/MS What is sampling by absorption of gases? What other terminology describes this process? Absorption is the process of transferring a gaseous compound into a uniform distribution in a liquid or solid. Involves the collection of gases, liquids, or solutes on a solid surface. Usually a porous solid is use, this provides vast surface areas. The less volatile a compound is, the more gas will be adsorbed. The quantity of a gaseous pollutant adsorbed by a given quantity of adsorbent depends on: Concentration in the air over the surface, Surface area of the adsorbent, Temperature, Other gases competing for adsorption sites and Properties of the adsorbate. These methods of sampling are also referred to as the wet collection system. 一 What does it mean when a filter is hydrophilic? The filter absorbs moisture or water. The filter has high affinity for water What kind of recycling can be done with contaminated soil? Most contaminated soil is used for study of possible decontamination or to study the degradation or persistence of the contaminant. Some contamination may also favor other forms of land use than others. Therefore contaminated soil may be used for other applications How can bio-fixation and biodegradation help to treat contaminated soil? Bio fixation involves the incorporation of particular organic material to aid in the regulation of other compounds that could be contaminants. An example of bio fixers is root nodules of some plants that fix nitrogen in the soil. Most organic compounds degrade naturally and are, therefore, termed to be biodegradable. Therefore, the concentration of biodegradable material reduces with time. List three examples of exploratory soil sampling. a) Single-industry wastes sites; this is where the waste composition is known, and the affected area is known. b) Small waste sites are sites in which the area involved is known, but the types of contaminants may be unknown. The sampling is designed to support qualitative analysis. c) Chemical spills: the affected area is visible; it can be that the soil has changed color, or there is no vegetation present What is a foodborne disease? 一 Foodborne illness is an illness that is carried in the food, to those who eat it. It may be caused by microorganisms such as Bacteria multiplying rapidly in food that is high in protein, such as meat or poultry. When is necessary to wash hands? Moreover, what is the proper way to wash your hands? –Wash your hands after using the restroom. –Wash your hands after any activity that may contaminate them (20 seconds). -Use a hand washing sink only. –Use single service hand towels or hot air dryers. What is the temperature dangerous zone? How long food can stay on the temperature dangerous zone? Temperature danger zones are temperatures that promote bacterial growth. The temperature danger zone ranges from between 40ºF to 140ºF (4.4ºC-60ºC) and food should be contained in these temperatures for more than four hours What are potentially hazardous foods? Potentially hazardous foods are fresh meat (beef or pork), poultry, seafood or fish, dairy products (milk and cheese). These are foods that without proper handling and storage could be contaminated and significantly contribute to illness. They require time and temperature controls/ these foods have high potential for bacterial growth. What is the difference between a Critical and Non Critical violation? Critical Violations are those Violations that pose an immediate threat to food safety and directly contribute to food contamination and/or foodborne illness. In contrast non, key violation does not have direct impact or threat on food safety though prolonged violations could be unfavorable to quality of food. They can be regulated in time to meet set standards What does date marking of ready to eat food means? Extended storage of potentially hazardous food could lead to the growth of pathogenic bacteria to dangerous levels to monitor and limit refrigeration time. Date marking ensures that refrigerated ready-to-eat (RTE) potentially hazardous food is either consumed or discarded within seven days. The activity is performed in instances dealing with potentially hazardous, Ready to eat, Refrigerated, and food stuffs held for more than 24 hours. Give a detail summary of a food establishment inspection procedure. –1st - assessing hazards –2nd - identify critical control points –3rd - set standards and criteria –4th - monitor your critical control points –5th - take corrective action if criteria is not met –6th - keep records –7th - verify that the system is working What is FATTOM? Is a mnemonic device that is used in the food service industry to describe the six favorable conditions required for the growth of foodborne pathogens. It is an acronym for food, acidity, time, temperature, oxygen and moisture. Using the Indiana State Department of Health Retail Food Establishment Sanitation Requirements (Food Code) classified the following violations as Critical or Non-critical and identified what section of the Food Code was violated. (20 pts.) 1. Food on container without a label. CRITICAL section 146 2. Potato salad found at 69 degrees F. critical section 177 3. Cleaner spray bottle without a label. 4. Food employee was wearing jewelry. Non-critical section 134 5. Meat cutters and knives found in debris and grease. Critical section 214 6. Hand-washing sink found with dirty towel and debris in it. Critical section 236/239 7. Grease trap clog and sewage backup. Critical section 378/375 8. Flies and roaches observed in the kitchen area. Non-critical section 162 9. Ready to eat food no label with date in the refrigerator. Critical 146/191 10. Not thermometer in the refrigerator and freezer. Non critical 218/254/197 11. Establishment did not have strips to check concentrations of sanitizers. Non critical section 131/291/294 12. Dishwashing machine did not reach the proper concentration of sanitizing solution. Critical 131/281 13. Food was stored on the floor. Critical section 178 14. Wet wiping cloths not stored in sanitizing solution. Critical section 301 15. Light bulb in the refrigerator found without protective shielding. Non critical 16. Dishwashing detergent found stored next to potatoes and rice. Critical section 200/295 17. No certified food handler on staff. Critical section 118 18. Observed employee with cut finger handling ready to eat food without protective gloves. Critical section 133 19. Employee was smoking a cigarette in the kitchen area. Critical section 136 20. Observed raw meat thawed in a sink full of water. Critical section 182/199 21. Problem (10 points): Using a PM10 Hi-Vol sampler, a 24 hr. sample was collected. The initial and final readings were as follows: Initial reading final reading flow rate (m3/min) 1.6 1.4 filter paper weight (g) 4.500 5.200 1. What is the concentration of PM sample? (µg/m3). = 106 = 324074.07 µgm-3 2. If the sampling time is 12 hr and the initial and final flow are 1400 L/min and 1100 L/min, respectively, what is the PM concentration in the sample? (µg/m3). 106 = 810.19 µgL-1 = 0.8012 µgm-3 HINT: C = Wf - Wi X 106 V V=average flow rate x sampling time Work Cited Indiana State Department of Health .Retail Food Establishment Sanitation Requirements Title 410 Iac 7-24. 2014. Print. Read More