Atomic absorption spectroscopy was used to determine the amount of aluminum in a sample of sunscreen. A blank solution was measured seven times to determine the detection and quantitation limits of the spectrometer. The blank readings were: 0.0073, 0.0082, 0.0110, 0.0101, 0.0102, 0.0098, and 0.0090 AU. Determine the signal at the detection limit and the signal at the limit of quantitation for this method. signal detection limit: signal limit of quantitation:

The lithium concentration in serum taken from a patient being treated with lithium for manic-depressive illness was analyzed using flame emission spectroscopy. A sample of the serum gave a reading of 283 units for the intensity of the 671 nm red emission line. Then, 1.00 mL of a 11.5 mM lithium standard was added to 9.00 mL of serum. This spiked serum gave an intensity reading of 633 units at the 671 nm emission line. What is the original concentration of Lit in the serum? [Li*] = mM Create Your Account stv hulu G Search or type URL 24 & 4 5 6 7 R Y G K * CO

4.) A solution’s transmittance is 35.0%. What is the transmittance if you dilute the solution to half of its initial concentration?

How does a two-dimensional NMR spectrum differ from a one-dimensional spectrum? In a 2-D NMR spectrum, what is the diagonal, and what leads to the cross-signals (cross-peaks)?