Estimation of heavy Metal (Lead, Chromium, Cadmium, Zinc, Copper, Arsenic) in Fresh Milk by AAS (Atomic Absorption Spectrometer) খসড়া Abstract: This project was aimed to measure the concentration of Lead (Pb), Chromium (Cr) and Cadmium (Cd), in brands of full cream powder milk available commercially in Harar using Atomic Absorption spectrometer. To this effect samples of three different brands of full cream milk powder were collected from Harar local market, Each of 3 ml of fresh milk samples were wet digested in 5ml of HNO3 (69-72%) and 3ml HClO4 (70%) for 2:30 h at a temperature of 210 0C. The wet digestion procedure was tested by varying reagent volume, digestion time and digestion temperature to develop a procedure that consume less reagent volume, clear solution, that requires minimum digestion time and minimum digestion temperature applied. The concentrations of heavy metals (Pb, Cr and Cd) in the powder milk collected from Harar were determined by using flame Atomic Absorption spectrometer. Concentration of Lead, Chromium and Cadmium in the powder milk brands were found to be in the range: 0.038-0.1688ppm, 0.0597-0.222ppm, and ND for sample X and Z but 0.068ppm for sample Y, respectively. The accuracy of the optimized procedure was evaluated by analyzing the digest of the spiked samples. The recoveries of the metals were in the range of 95.91-99.3% and the standard deviations were less than 10%. These values are compared with recommended dietary allowance (RDA)
We know that that the end point of the titration is reached when, after drop after careful drop of NaOH, the solution in the flask retains its pale pink color while swirling for about 30
The lead in the environment is formed naturally in the earth’s crust mainly as Lead Sulphide. The main exposure channels of lead entering the environment through atmospheric lead is predominantly from automobile emissions. Other lead exposure routes include lead-acid batteries, paint chips, fertilizers, utilized ammunition, pesticides, and other industrial byproducts. The means of conveying lead from key emission sources is mainly through the air. Concerning the sources of lead in drinking water, normally lead reaches into the residents’ water after it is channeled from their water treatment plant or the wells. To be more precise, the source of lead in people’s water supply largely emanates from their households’ pipes or lead solder from plumbing. The most typical cause of the lead formation is from the corrosion reaction by the lead pipes or solders and the water. The acidity as a result of the low pH, dissolved oxygen, and little mineral contents in the water are main reasons of the corrosion. The lead amounts in the water become high if the water spends a long duration of time stagnated inside the old pipes.
While the prevalence of lead poisoning in children is decreasing in the United States, screening of lead levels remains an important task of the pediatric primary care provider. Risk factors for lead poisoning and its toxic effects include children under six years (and especially those between 12 and 36 months), inner city children living in deteriorating housing, low-income and middle-income children, and refugee and foster care children (Hurwitz & Lee, 2013a). The importance of this screening is underscored by the fact that children can be asymptomatic even with high blood lead levels (BLL) and symptoms of lead toxicity can be non-specific. Early diagnosis is crucial because there are significant and permanent effects to almost all body systems with both toxic and below toxic BLL, including neurologic (ranging from developmental delay and behavior problems to encephalopathy), hematologic (anemia), renal (lead nephropathy), gastrointestinal (lead colic), and endocrine (vitamin D deficiency) (Hurwitz & Lee, 2013a). Laboratory evaluation of lead poisoning in children will now be discussed.
11) Dry out the methylene chloride solution that contain the benzoin and the dibromobenzene by the use of anhydrous sodium sulfate.
The data gathered and calculated in the experiment accurately portrayed the way the reactions would have taken place. The chloride analysis was a little bit off from other groups due to the fact that our AgCl was in clumps, creating less surface area, thus our product took longer to burn and may not have burned correctly compared to other groups; yet there are several experimental factors that could have caused us to have different results than other groups, i.e. different measurements for samples. Our sources of error could have included eye measurement error, timing of set solutions error, measurement errors, and small calculation errors. Among other variables, the calibration of the analytical balance and spectrophotometer could have
But the result met the expectation because the color of the solution was reached the end point by changing from red to blue. The primary errors may occur because of misreading the buret while measuring the volume of EDTA. Another error can affect the result of the experiment was that letting the volume of EDTA excess the ending point; so that the volume of EDTA was overapply that lead error. The last source of error was that our unknown sample had high percentage in mass of Mg2+, so that we need more than 50 ml of EDTA( which was the capability of the buret) to reach the end point. We had to refill the buret while measuring; and also the large volume of solution made the color harder to recognize the end point. That also led to error.
Lead poisoning has been a concern for many years. In fact, because of the affects of lead poisoning, there has been an extensive decline in its use. "Many people believe lead poisoning is no longer a threat, yet millions of homes contain lead based paint" (Heck, J., 2005, para. 1). Exposure to lead at any level is unhealthy, especially in infants, children, and pregnant women and continues to be an ongoing dilemma in this country. I read two articles concerning lead poisoning; the first article is from FineTuning, a popular press and the second article is from Pediatrics, a peer-review journal. In this paper, I will clearly summarize each article by comparing the content of both articles. In addition, I will summarize the attention to
If there are 1000 meters in a kilometer, how many meters are there in 0.05 km? 50 meters.
According to ( Compton's by Britannica, 2011, SIRS discover) Lead is found in tap water and other water sources which is toxic metal
Preparation is a key to success in this lab. For this reason, you are required to thoroughly read through the experiment information presented in the lab manual, and complete a pre-lab for each experiment you do. The prelab must be completed prior to the day of the experiment. Each Friday I will ask to see your completed prelab before I allow you to enter the lab. If you have not finished the pre-lab, I will not allow you to enter the lab and you will receive a zero.
One or two checks and tests were put in place in order to validate the data trends. A colorimeter was used as a more scientifically consistent measure of milk clarity: (one sample was taken from each temperature setting) and mean readings were calculated from the table results to hopefully reduce the effect of moderate outliers.
From the information in each of these tests, a Cation logic tree was formed for easy identification of
In test 1, concentration of four metal which are arsenic, cadmium, lead, mercury was recorded and were compared with record which was ken six months ago. The concentration of mercury has increase for 0.19*10-2 mg/L to 0.23*10-2 mg/L. The concentration cadmium
A Cobalt-Amine-Halide compound is synthesized from cobalt (II) chloride hexahydrate. An orange-tinted solid is produced and is considered to be unknown since the specific ligand amounts are unknown. By determining the percent composition of various elements and compounds in the unknown, its true identity can be predicted. Chloride, ammonia, and cobalt are three examples of percent compositions determined to help narrow the selection of possible unknowns. Titrations using Na2S2O3 and HCl to determine percent cobalt and ammonia, respectively, are used. Silver nitrate is used to precipitate the chloride ions in the unknown, which can be measured to determine the percent composition of chloride
Lead poisoning is one of the global burden and need to be focused a lot on preventive strategies.