The following results were obtained from an analysis of copper content in four representative samples using flame atomic absorption spectroscopy. Suppose the true value is environmental 5.10 ppb. Sample 1 2 3 4 Cu content (ppb) 5.34 5.37 5.44 5.22 Comment on the data obtained in terms of accuracy and precision. (iii)

The following results were obtained from an analysis of copper content in four representative samples using flame atomic absorption spectroscopy. Suppose the true value is environmental 5.10 ppb. Sample 1 2 3 4 Cu content (ppb) 5.34 5.37 5.44 5.22 Comment on the data obtained in terms of accuracy and precision. (iii)

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter2: Basic Statistical Analysis With Excel

Section: Chapter Questions

Problem 10P

See similar textbooks

Similar questions

Use the data in Figure 4.8 to estimate the ratio of radiation intensity at 10,000 Å (infrared) to that at 5000 Å (visible) from a blackbody at 5000 K. How will this ratio change with increasing temperature? Explain how this change occurs.
(a) A sample of body serum is to be analysed for sodium by flame emission spectroscopy. 1.00cm3 aliquot of serum was pipetted into each of two 50.0 cm3 volumetric flasks. The firstflask was diluted to volume with deionised water. The absorbance of this first solution was0.350. To the second flask 10.0 cm3 of a 25.0 ppm sodium standard was added and theflask made up to volume with deionised water. The absorbance of this second solution was0.720.(i) Calculate the concentration of the sodium in the body serum in mg dm–3
A sample of body serum is to be analysed for sodium by flame emission spectroscopy. 1.00cm' aliquot of serum was pipetted into each of two 50.0cm' volumetric flasks. The first flask was diluted to volume with deionised water. The absorbance of this first solution was0.350. To the second flask 10.0 cm' of a 25.0 ppm sodium standard was added and the flask made up to volume with deionised water. The absorbance of this second solution was 0.720.(i) Calculate the concentration of the sodium in the body serum in mg dm-3.
Flame Atomic Absorption Spectroscopy (FAAS) method is selected due to its wide applicability for metal ion analysis in drinking water samples. Provide appropriate discussion to determine the concentration of selected heavy metals (Cu and Cr) in the unknown tap water sample.
Express a wavelength of 442 nm as (a) a frequency. (b) a wavenumber.
Inductively coupled plasma-optical emission spectroscopy (ICP-OES) is a quantitative method for determining trace elements in liquid samples. ICP-OES and other methods of spectrochemical analysis are typically subject to errors due to the present of interferences. It had been reported that ICP-OES is significantly affected by spectral interference, but relatively less affected by the chemical interferences. (i) Explain why ICP-OES is significantly affected by spectral interference but less affected by chemical interferences.
Potassium dichromate and potassium permanganate have overlapping absorptionspectra in 1M H2SO4 . K2Cr2O7 has an absorption maxima at 440 nm, and KMnO 4 has a band at 545nm (the maximum is actually at 525 nm, but the longer wavelength is generally used whereinterference from K2C2O7 is less). A mixture is analyzed by measuring the absorbance at these twowavelengths with the following results: A 440 =0.405, A 545 =0.712 in a 1-cm cell. The absorbances ofpure solutions of K2Cr2O7 (1x10 -3 M) and KMnO 4 (2.00x10 -4 M) in 1 M H 2 SO 4 , using the same cell gavethe following results: A Cr,440 = 0.374, A Cr,545 = 0.009, A Mn,440 =0.019, A Mn,545 = 0.475. Calculate theconcentrations of dichromate and permanganate in the sample solution.
5- In Trans-[PDFC1;]° determine I'total, I'tran., I'rot. and I'vib., Which mode(s) is (are) active in IR and Raman spectroscopy?
3. Explain the main differences between flame atomic absorption spectrophotometry and UV-VIS molecular absorption spectrophotometry in terms of: (a) (b) energy levels and transitions; main instrumental features.
Explain why an internal standard is required during sample preparation in quantitative analysis when using atomic spectroscopy?
(i) Explain why Beer's Law breaks down when absorbance values are < 0.005. (ii) Explain the operation of a calcium source used in atomic absorbance spectroscopy. (iii) Explain why the calcium source described above will not operate for the quantification of magnesium.
(a) Draw a block diagram of an atomic absorption spectrometer (AAS). Briefly describe the function of each components. (b) What is the process of atomization in atomic absorption spectrometer? Describe the steps of the process in the correct sequence. (c) State TWO interferences that are encountered in atomic absorption spectrometer. Suggest ONE solution to overcome the problem. (d.) What is the main difference, in terms of instrumentation, between atomic absorption spectrometer and atomic emission spectroscopy?