5. AOACSPDSMethods-2018AwardsV3

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68 V aclavik et al .: J ournal of AOAC I nternational V ol . 99, N o . 1, 2016

Figure 1. Impact of the mobile phase composition on peak shape and chromatographic resolution between isobaric analytes. (A) Mobile phase A/B: 0.1% FA in H 2 O/0.1% FA in MeOH. (B) Mobile phase A/B: 5 mM ammonium formate in H 2 O/5 mM ammonium formate in ACN. (C) Mobile phase A/B: 10 mM ammonium formate and 0.1% FA in H 2 O/10 mM ammonium formate and 0.1% FA in ACN:MeOH (1:1, v/v).

search of these m/z values in AIF records can be used to detect nontargeted, novel PDE5 inhibitor adulterants based on their structural similarity to known PDE5 inhibitors.

SMPR 2014.011. This method showed excellent repeatability with RSD r values of 0.4–1.8%, well below the repeatability criteria of ≤20% in AOAC SMPR 2014.011.

POI

Recovery and Repeatability

Detection and identification results are summarized in Table 5. In total, 1575 data points were evaluated to demonstrate POI and also probability of detection (POD) for detection/ screening of PDE5 inhibitors. Correct detection/identification results compliant with identification requirements provided in the European Commission Decision 2002/657/EC (9) were obtained for all evaluated analytes at all concentration levels and in all matrixes. The method validation results fulfilled the

Results of recovery experiments conducted in triplicate at 50 mg/kg in a capsule sample in M5 are presented in Table 4. The test level of 50 mg/kg was selected for this evaluation to demonstrate the method performance at the target LOQ of AOAC SMPR 2014.011 for the determination of PDE5 inhibitors (6). The mean recoveries ranged from 69 to 90%. Only one target compound (thiohomosildenafil) was slightly below the recovery range of 70–120% provided in AOAC