108139-1 Study Title Data Requirements Author Study ... - IR-4 Project

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Bayer Corporation 108139-1 Agriculture Division 3.5 Method Validation 3.5.1 Requirements 1. Analyze three unfortified control samples and three fortified control samples at the LOQ, using three different control samples when possible. 2. Recovery values must fall between 70% and 120%. 3. The control ppm value must be less than 20% of the fortification ppm level. 4. (DFK *& 06 PHDVXUHPHQW RI D UHFRYHU\ ZDV FRPSDUHG WR D J P/ (0.050 ppm) quantitation standard containing cyfluthrin and [ 2 H6]cyfluthrin. All recovery samples must fall within the linearity curve. 5. The correlation coefficient from the linear regression of the response factors of the linearity curve points, as described in 3.4.4 D, must be greater than 0.99. 6. Calculate recoveries by the following equation: 3.5.2 Recovery Procedures ppm found – control ppm Recovery = X 100% ppm fortification level 1. Fortify aliquots of control matrix (in the 4 oz glass bottle beaker that was used for the 5 gram sample extraction) with the appropriate secondary standard using a / JDV WLJKW V\ULQJH WR DSSO\ WKH DSSURSULDWH VWDQGDUG VROXWLRQ IRU WKH recovery level desired. An example is given below. SSP / RI WKH J P/ VHFRQGDU\ VWDQGDUG VROXWLRQ 2. Proceed to sample extraction (Sec 3.4.2.1, Step 2, Sec 3.4.3.1 Step 2, or Sec 3.4.3.2 Step 2). 4.0 Results and Discussion A flow diagram of the residue analytical method is presented in Figures 2 thru 4. 40
Bayer Corporation 108139-1 Agriculture Division 4.1 Sample Extraction (Except Nutmeat), Liquid/Liquid Partition, and Florisil Clean-up The extraction described in the original method 1 was retained except for a reduction in sample weight with corresponding decrease in solvent volumes and the addition of HCl. HCl was used in corn fodder in the original method due to the basic nature of the matrix. The extraction using MeOH / aqueous 1.2 N HCl (4:1, v/v) followed by MeOH was considered adequate for the release of cyfluthrin residues. The method continued with a liquid/liquid partition. The aqueous phase containing the sample was partitioned versus acetone / DCM (1:2, v/v). The cyfluthrin was transferred to the organic phase. Many polar compounds extracted using the polar extraction solvents were left behind in the aqueous phase. The method ends using normal phase absorption chromatography (2.5% deactivated florisil) where the cyfluthrin was loaded onto the florisil in hexane, washed with hexane and selectively removed with hexane/acetone (9:1, v/v). Any compounds that have a stronger retention than cyfluthrin was left behind on the florisil packing. 4.1.1 Sample Extraction (Apple and Pear Only), and Florisil Clean-up The extraction described in the original method 1 was retained except for a reduction in sample weight with corresponding decrease in solvent volumes and the addition of HCl. HCl was used in corn fodder in the original method due to the basic nature of the matrix. The extraction using MeOH/aqueous 1.2 N HCl (4:1, v/v) followed by MeOH was considered adequate for the release of cyfluthrin residues. The method continued using normal phase absorption chromatography (2.5% deactivated florisil) where the cyfluthrin was loaded onto the florisil in hexane, washed with hexane and selectively removed with hexane/acetone (9:1, v/v). Any compounds that have a stronger retention than cyfluthrin were left behind on the florisil packing. 4.1.2 Sample Extraction (Nutmeat Only), ACN / hexane Partition, and Florisil Clean-up Due to the oily nature of the nutmeat, the original extraction procedure was not yielding acceptable recoveries. The nutmeat sample was placed on a Soxtec and boiled for 2 h in 50 mL of hexane followed by a 1 h rinse. The method continued with a ACN / hexane partition where the cyfluthrin was transferred to the ACN phase. The oily compounds were left behind in the hexane phase. The ACN phase was partitioned once more with clean hexane and concentrated to dryness. The sample continued through the florisil clean-up as described in Section 4.1. 41
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