As part of a drug registration submission document it is necessary to supply a validated analytical method using ICH 2QB regulations. These regulations are used to provide an analytical method to check the safety and efficacy of the product. In this assignment you are provided with data for TWO alternative methods for the assessment of the toxic metal Pb in drugs. No knowledge of the techniques is necessary since the assessment will be based solely on the calculations resulting from the data provided. Please make sure you use the proforma provided to submit your work. The question is very simple:
Which technique would you recommend and why?

Technique 1 – Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES)
Technique 2 – Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

You are asked to take the data provided and assess the Linearity, Accuracy, Limit of Detection (LoD), and Limit of Quantification (LoQ).

1) Linearity
Use the data below to assess the linearity of each of the techniques. This will involve the construction of a fully labelled calibration graph for each technique. Only supply the graph to the last concentration where the graph is linear. Clearly explain how you reached the decision and explain which technique you would select on linearity and why
ICP-OES ICP-MS
Concentration µg/ml    Signal/ cts Concentration µg/ml Signal/ cts
0                                        5                         0                         48
0.01                                  45                      0.01                      467
0.1                                     480                   0.1                         4512
1                                        5067                   1                         51256
10                                     46987                10                         445712
100                                  490023             100                      5501720
1000                               4051230             1000                      46612980
10000                               22445678          10000                   511887320
100000                            401125645       100000                4534217840
1000000                         698765432       1000000                23547823980

2) Accuracy
In order to assess the accuracy of each technique a sample of a standard reference material NIST SRM 3280 was analysed. The certificate of analysis (COA) is available on Blackboard and attached for you to consult. The preparation of the standard is given below. Using the data provided check the recovery of Pb obtained for both techniques.
A 0.2547g sample of NIST 3280 was digested in 10ml of nitric acid (8ml) and hydrochloric acid (2ml). The resulting solution was diluted to 25ml. This was then analysed by both ICP-OES and ICP-MS. The resulting solution gave the following results after a triplicate analysis
ICP-OES 2.64 ± 0.21 ng/ml
ICP-MS 2.81 ± 0.08 ng/ml

Using the numbers above calculate the % recovery, and comment on the results and the variability in the data provided

3) Limit of Detection (LoD) and Limit of Quantification (LoQ)
The calibration data below was gained by using a calibration graph with 6 standards for each technique. The blank was then analysed 10 times. You are provided with the mean, standard deviation and the equation of the calibration line in each case. Calculate the limit of detection (LoD) and limit of quantification (LoQ) for each technique.
ICP-OES
y = 5.218x - 0.8683 R² = 0.9937
Blank Average = 1.52
Blank SD = 1.16
ICP-MS
y = 45.903x - 0.8549 R² = 0.9991
Blank Average = 15.34
Blank SD = 0.731
Comment on the LoD and LoQs obtained for this determination

Finally summarize the information you have obtained and select one of the techniques.

Linearity – ICP-OES – Insert the calibration graph to the last point of linearity
What is the last concentration that is linear for the ICP-OES
How did you reach this conclusion?
Linearity – ICP-MS - Insert the calibration graph to the last point of linearity
What is the last concentration that is linear for the ICP-MS
How did you reach this conclusion?
Which Technique is Most Linear?
What overall conclusion can be drawn about the linearity of both techniques and why is this important?

2) Accuracy
Calculate the percentage recovery of Pb for each technique clearly showing your calculations. This should be done using the SRM 3280 certificate to obtain the ‘true’ value of Pb
ICP-OES Calculation
ICP-MS Calculation
Comment on the % Recovery obtained
Comment on the Variability in the results

3) Limit of Detection (LoD) and Limit of Quantification
a) Calculate the LoD and LoQ for ICP-OES – Show all calculations
b) Calculate the LoD and LoQ for ICP-MS – Show all calculations
c) Comment on the LoD and LoQ results obtained

4) Summarize the Data Obtained and state your conclusions

5) Which techniques would you select?

As part of a drug registration submission document it is necessary...