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Nov. 25th, 2007 09:15 pmThere go 20 hours of my life.
Let me back up for a minute: I was trying to measure the amount of phosphorus in a bunch of different samples. To do so, I basically add some chemicals that react with the phosphorus in the samples and make the samples turn blue. The amount of blue is directly proportional to the amount of phosphorus in the sample.
But how do I attach numbers to these things? Part of the process involves measuring the blueness of a bunch of samples whose phosphorus content I know in advance (because I put all of the phosphorus in there). Then I can create a line graph of the relationship between the amount of blue (measured as a sample's absorbance of light in a spectrophotometer) and the amount of phosphorus. This line is known as a standard curve, and so if I know a sample's blueness, I can use the standard curve to estimate its phosphorus content.
But there are some tricks to this debacle: one's standard curve must be very, very accurate. All of the points of the known samples must line up right on the line, and the samples that are supposed to contain zero phosphorus should not develop any blue color.
I was cautiously optimistic today when I approached the finish line because my zeros were zero. But alas, the points do not line up on the line, so I cannot say with any certainty how much phosphorus is in my samples.
This is a frustrating result after 20 hours of work, and means at least another 20 hours more, if not more than that.
Ugh. Time to sleep, and then I have a dissertation committee meeting first thing in the morning. Double ugh.
Let me back up for a minute: I was trying to measure the amount of phosphorus in a bunch of different samples. To do so, I basically add some chemicals that react with the phosphorus in the samples and make the samples turn blue. The amount of blue is directly proportional to the amount of phosphorus in the sample.
But how do I attach numbers to these things? Part of the process involves measuring the blueness of a bunch of samples whose phosphorus content I know in advance (because I put all of the phosphorus in there). Then I can create a line graph of the relationship between the amount of blue (measured as a sample's absorbance of light in a spectrophotometer) and the amount of phosphorus. This line is known as a standard curve, and so if I know a sample's blueness, I can use the standard curve to estimate its phosphorus content.
But there are some tricks to this debacle: one's standard curve must be very, very accurate. All of the points of the known samples must line up right on the line, and the samples that are supposed to contain zero phosphorus should not develop any blue color.
I was cautiously optimistic today when I approached the finish line because my zeros were zero. But alas, the points do not line up on the line, so I cannot say with any certainty how much phosphorus is in my samples.
This is a frustrating result after 20 hours of work, and means at least another 20 hours more, if not more than that.
Ugh. Time to sleep, and then I have a dissertation committee meeting first thing in the morning. Double ugh.
