Example: A GC-FID analysis was conducted on a soil sample containing pollutant X. The following separations were conducted: t,(minutes) peak area 21.1 ppm Toluene nternal Standard 33.4 ppm X Injection 1 10.11 36,242 14.82 45,997 Injection 2 21.1 ppm Toluene Internal Standard 10.05 38,774 unknown concentration X 14.77 39,115 What is the concentration of X in the sample?

Example: A GC-FID analysis was conducted on a soil sample containing pollutant X. The following separations were conducted: t,(minutes) peak area 21.1 ppm Toluene nternal Standard 33.4 ppm X Injection 1 10.11 36,242 14.82 45,997 Injection 2 21.1 ppm Toluene Internal Standard 10.05 38,774 unknown concentration X 14.77 39,115 What is the concentration of X in the sample?

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter15: Electrophoresis And Other Separation Methods

Section: Chapter Questions

Problem 5P

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1. Use the following Absorbance Data to generate a Bradford Assay Standard Curve. Protein Concentration Absorbance at 595nm (mg/mL) 0.05 Chart Title 0.0092 0.1 0.02 0.2 0.04 0.3 0.112 0.4 0.167 0.5 0.1980 0.6 0.2436 Absorbance at 595nm 0.3 4y = 0.4499x - 0.0254 R? = 0.9824 0.25 0.2 0.15 0.1 0.05 0.1 0.2 0,3 0.4 0,5 0.6 0.7
Mercury is present in Lake Miramar at a total concentration of 20.4 ng/L. Lab tests suggest an average solids partition coefficient of 105L kg-1 What is the dissolved phase concentration if the particle concentration is 25 mg L-1?
A 0.0200 gram blood sample was decomposed by a microwave digestion technique followed by dilution to 100.0 mL in a volumetric flask. Aliquots of the sample solution were treated with a lead complexing reagent and water as follows: Solution 1: 10.0 ml blood sample + 20.0 mL complexing agent + 30.0 mL H20. Solution 2: 10.0 ml blood sample + 20.0 mL complexing agent + 26.0 mL H20 + 4.00 mL of 78 ppb Pb2+ standard. The resulting solutions were analyzed by UV/Vis at 375 nm. Absorbance for solution 1 = 0.155 and for solution 2 = 0.216. Calculate the concentration of lead (ppb) in the original sample.
In order to improve the peptide separation by using a HPLC system, trifluoroacetic acid acts as mobile-phase modifier was added during the preparation of mobile phase. The preparation was performed by a postgraduate student as following:“2.851 g trifluoroacetic acid (MW: 114.02 g/mol) was made up to 500 cm3 in a graduated flask. To this solution, 50 cm3 of ethanol was added, and after mixing the mobile phase was placed in the solvent reservoir and pumping was commenced at 1.5 cm3 min-1.”Based on the given preparation procedure, identify THREE mistakes that were made.
3. This is the standard procedure for determination of nicotine in urine. A 1.00mL sample was placed in a 12mL vial 5-aminoquinoline was added as the internal standard (5 ug). The sample was monitored using mass spectrometry at m/z values for nicotine (84) and the internal standard (144). Given the following data determine the concentration of the two unknown samples Nicotine (ug/L) Area Area 12 0.056 0.059 51 0.402 0.391 102 0.684 0.669 157 1.011 205 Unknown 1 Unknown 2 1.278 0.51 1.18 1.063 1.355 0.53 1.32
(B) Relative intensity 100 15 m/z 20 3.0 40 55 60 71 80 8.6 (CH3)2CHCH₂CH₂NHCH₂CH₂CH(CH3)2 100 100a 100 114 128 120 142 CH₂CH(CH₂ 140 157M+. 160
A. Draw structure of compound. B. Label base peak and molecular ion peak.
The method of internal standard was used to analyze and measure the concentration of chemical X by GC A known mixture of compounds X and Y (internal standard) gave the following chromatographic results: Compound X Y a) 2.0 x 106 M b) 8.4 x 10-7 M c) 6.6 x 10-7 M Concentration (M) 6.3 x 10-8 2.0 x 10-7 d) 4.1 x 10-7 M e) 2.9 x 10-7 M Peak Area Then, an unknown was analyzed as follows. 3.0 mL of unknown X was treated with 0.100 mL of 1.6 x 10-5 MY and the mixture diluted to 10.0 mL final volume. Peak areas were 633 (for X) and 520 (for Y). What is the concentration of X in the unknown. (The original 3.00 sample?) 395 787
The following equation describes the dependence of the rate constant (k) with the temperature in dynamic NMR. kgTc -AG*. exp (- RT. k = C where kg and h are physical constants, R is the ideal gas constant, T. is the coalescence temperature and AG* is the activation energy? The following table shows the units of some of these parameters. Parameters Units k s-1 To K h Js R JK-' mol-! AG* J mol- Does k increase with AG*? Explain your answer.
The following equation describes the dependence of the rate constant (k) with the temperature in dynamic NMR. kgTc exp (- -AG* RTc k = h where kg and h are physical constants, R is the ideal gas constant, T. is the coalescence temperature and AG* is the activation energy? The following table shows the units of some of these parameters. Parameters Units k s-l T. K h Js J K-' mol- J mol- R AG+ What are the units of kg? Show your analysis.
percentage purity of an ibuprofen sample was determined by a reversed phase HPLC method as follows: Y Der ● A calibration curve of peak area versus concentration (ug/mL) of pure ibuprofen was constructed The ibuprofen sample for analysis was prepared by taking 10.0204 g of powder and dissolving it in/1Lbf distilled water (solution A). 1 ml of the latter solution was further diluted to IL with distilled water (solution B). Solution B was analysed by HPLC analysis Results The equation for the best-fit line of the calibration curve is: y=26820x-1323.8. ● The average peak area for the ibuprofen sample (solution B) was 266796.2 Calculate the percentage purity of the ibuprofen powder.
b Answe X e Oefeni x Oefeni x Oefeni x Oefeni x A Oefeni X 2021 x Oefeni x Micros X com/forms/d/e/1FAlpQLSfSGcE8gf218c6JoHMWME1A8Nydf8M4g1yG93D-2LPpoMj g/formResponse Figure 12 NaNH2 CH3–I H20 CH3-C=CH Hg2, H* Question 13: Consider the synthesis scheme in Figure 12. Give the preferred IUPAC name of C? [Use lowercase letters. Do not use spaces if it is not required in the name.] * Jou antwoord Show all 10:08 28°C Sunny 2021/11/19 N