Bio Lab 2107
Is H20 Bad for You?
In the village of Gopher Hollow there’s a cluster of Blue Baby Syndrome. There were four infants affected by this cluster. The families from the infants would collect their water from wells. We have to determine what’s the source of the high levels of nitrites in the water. The four sources that could be the point of contamination are a new subdivision, textile plant, an organic farm, and a mountain lake. We had to ﬁnd the concentration of each known standard and unknown standard. We did this by using a spectrophotometer. The results were the following, the organic farm with a herd of 50 cows and a 10 acre ﬁeld of zucchini had the highest levels of nitrites. Introduction:
Blue Baby Syndrome is a condition that affects many infants. This condition makes the baby’s skin turn blue because of the lack of oxygen. This condition can exhibit lethargy, vomiting and not being able to breathe. It can even lead to death in rare cases. This condition is caused by the excess amount of nitrate that is then converted into nitrite by the digestive system. The hemoglobin then reacts with the nitrites to form Methemoglobin. Methemoglobin is not a problem in adults since they have an enzyme that converts methemoglobin back to hemoglobin. Infants don’t have many of the enzyme to convert methemoglobin to hemoglobin, resulting in Blue Baby Syndrome. For
example in Gopher Hollow there is a cluster of Blue Baby Syndrome. Four infants have been affected. The families of these infants all collect their water from a community well. Nitrates and Nitrites can be found in many things. For example in vegetables, like carrots, lettuce and spinach. We do get many of our nitrogen from the food we eat but also through the water we drink.(1) Levels above 10 ppm of Nitrate/ Nitrites are not dangerous but accumulations of it in soil and groundwater can cause high levels of these compounds.(1) Causing high level of nitrites in drinking water and especially in wells. If a mountain lake that has become overgrown with algae then there could be an increase of Blue Baby Syndrome cases. The lake could be a main water source. Methods:
The ﬁrst step in determining the culprit location is to create a graph that represents the relationship between the amounts of nitrites in the solution and the optical density of standards of known concentrations. These standards are the control group. Then a spectrophotometer was turned on was allowed to warm up for 15 minutes. There were nine standards to be tested using the spectrophotometer. One ml of each standard was labeled and placed in 13 by 85mm glass test tubes. The concentrations were: distilled water, 0.5ppm, 1.0ppm, 2.0ppm, 4.0ppm, 6.0 ppm, 10.0 ppm, 20.0 ppm, and 40.0 ppm. Using the P20 micropipettor, 20 microliters of the color indicator reagent ( 1naphthylethylenediamine sulfanilamide) was added to each standard sample and mixed throughly. A new micropipette tip was used to prevent mixing of chemicals. The samples were left out to sit for ﬁve minutes to insure full color development. Then the spectrophotometer’s wavelength was set to 550nm because the nitrite indicator absorbs light at 55onm(1). I ml of the distilled water sample was transferred into a clean cuvette
using a plastic transfer pipette. The cuvette was then placed inside the spectrophotometer . The button labeled “blank” was pressed and the OD reading was 0.000A . After getting the OD, the blank sample was placed back into its original test tube. Then 1 ml of the 0.5ppm standard was transferred into a clean cuvette and placed inside the spectrophotometer for OD measurement. Once the measurement appears on the screen record it. This step was repeated for the remaining standard samples. After measuring the OD each sample was transferred back into its original test tube. With the data collected, a graph was plotted with the Optical Densities on the vertical axis...
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