Add 1 mL each of QC-spike solution check consistency. Calibration spike standards in MeCN for 2 Prepare the necessary number of appropriate centrifuge tubes 27 pesticide analytes make 10 mL each in volumetric flasks, then 2 mL mini-centrifuge tubes or 10—15 mL centrifuge tubes transfer to 15 mL dark glass vials and store in freezer.
Add 1. If no planar pesticides are among the analytes e. Note: Final extract volume may have to be reduced to 0. An appropriate chopper must be used to 1a Test mix for GC in toluene. An uncommon or 30 compounds to be analyzed. Blend the sample until it gives a consistent texture.
The test portion e. Dilute QC-spike solution. To provide the most homogeneous comminuted samples, frozen 5a Cal-standard In this case, cut the sample into 2—5 cm3 portions with a knife and store 6a Cal-standard Options for Handling Extracts for Analysis solution and fill to the mark with toluene.
Option A. Step 8, then double all volumes given. IS in toluene. These concentration and organic solvent content at the initial LC mobile instructions will be given for 15 g samples extracted in 50 mL FEP phase conditions e.
Safety notes: formic acid aqueous solution. In centrifugation, do not exceed the analytical sequences according to H. Weigh Do not add the IS solution to the 2 or concentration and organic solvent content at the initial LC mobile 6 matrix blanks to be used for matrix-matched calibration standards.
The appropriate vials. Combine the 6 matrix blank extracts if anhydrous MgSO4 to reach the 0. In GC, ensure that peak shapes considerably better than the other. It is anticipated that some analytes will be standards in the plot used.
Perform maintenance to calculations, except when calibration plots were very poor. Figure 2 correct problems if poor GC quality is observed for those analytes of the collaborative study [J.
Use alternate or additional examples of calibration curves that yielded untrustworthy results. In that case, inject the 0-standard to determine if significant misintegrations, or mislabeling are the likely causes for those interferences are present at the tR of the analyte s. Statistical Analysis of the Results for the analytes. No evidence of statistician and AOAC volunteer, John Phillips, also calculated the carry-over should be present in the reagent blank.
Comparison of the results was made, and the sample preparation, but degradation of certain pesticides in the causes of any discrepancies were corrected until all results were in extracts will likely occur during prolonged storage.
Data Analysis The SD evaluated the data in several different ways entailing the Quantitation is based on linear least squares calibration of analyte use of an IS or not. The statistician only evaluated the data without peak areas plotted versus analyte concentration.
The y-intercept use of an IS, and in these cases, outliers were removed for statistical should be near zero and correlation coefficient r2 of the line should reasons only. Peak heights test and reproducibility among laboratories Grubbs outlier test.
This relationship If a well-characterized quadratic relationship occurs, then a provides an easy comparison of the results from this collaborative best-fitted quadratic curve should be employed for calibration study with other collaborative studies that were used to calculate the instead. Horwitz equation [Horwitz, W.
A spreadsheet was provided to all collaborators that automatically J. Figure 1 of the collaborative study [J. Essentially, a ] shows a small section of the spreadsheet for Laboratory HorRat value between 0. The collaborators entered the analytical conditions, integrated acceptance criteria for AOAC in collaborative study trials [Horwitz, peak areas, tR, and quantitation ions used for each analyte into the W.
In pesticide appropriate cells in the spreadsheets. Related Papers Validation of a fast and easy method for the determination of residues from pesticides in fruits and vegetables using gas and liquid chromatography and mass … By fatima murshed. Download PDF. Combines elements of the preceding searches Text, Category, and Full Text. Search Methods by Keyword. This exact phrase Any of these words All of these words. Category Search. Full Text Search. Advance Search. Guide to method format Definition of terms and explanatory notes.
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