OMB First to Final Action Recommendation Checklist 11-12-18

C HANG ET AL .: J OURNAL OF AOAC I NTERNATIONAL V OL . 99, N O . 4, 2016 1055

Table 2. Degradation equations of 20 representative pesticides in aged Oolong tea at c and d concns over 90 days by GC-MS/MS a

c Concn

d Concn

R 2

R 2

No.

Pesticide 7ULÀXUDOLQ 7HÀXWKULQ

Initial value (TXDWLRQ RYHU

GD\V

Initial value (TXDWLRQ RYHU

GD\V

1 2 3 4 5 6 7 8 9

214.4 106.1 116.9 119.6 114.7 240.3 116.7 113.0 451.7 116.0 451.7 117.9 234.0 115.9 965.0 116.8 112.9 118.6 237.4 46.2

\ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [

0.548 0.742 0.693 0.512 0.822 0.702 0.533 0.543 0.794 0.686 0.768 0.587 0.717 0.667 0.579 0.763 0.653 0.571 0.524 0.74

248.6 122.6 124.7 126.6 126.2 267.4 130.5 126.3 466.9 124.2 466.9 120.3 236.0 116.4 966.0 118.9 114.8 119.4 240.0 51.9

\ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [ \ í OQ [

0.787 0.832

Pyrimethanil Propyzamide

0.77

0.598 0.873

Pirimicarb

Dimethenamid Fenchlorphos Tolclofos-methyl Pirimiphos-methyl

0.86

0.785

0.78

0.867 0.824 0.784 0.805 0.733 0.774 0.653 0.746 0.728 0.576 0.65

10 11 12 13 14 15 16 17 18 19 20

ƍ ''(

Bromophos-ethyl

ƍ ''(

Procymidone Picoxystrobin Quinoxyfen Chlorfenapyr

Benalaxyl Bifenthrin

'LÀXIHQLFDQ

Bromopropylate 0.647 a 7KH GHJUDGDWLRQ HTXDWLRQV ZHUH REWDLQHG E\ SORWWLQJ GHWHUPLQDWLRQ WLPH HYHU\ GD\V RQ WKH x -axis and concentration on the y -axis.

Table 3. Logarithmic functions of 20 pesticides in aged Oolong tea at d concn a No. Pesticide Logarithmic function R 2 1 7ULÀXUDOLQ \ OQ [ 0.705 2 7HÀXWKULQ \ OQ [ 0.641 3 Pyrimethanil \ OQ [ í 0.758 4 Propyzamide \ OQ [ í 0.620 5 Pirimicarb \ OQ [ í 0.800 6 Dimethenamid \ OQ [ í 0.807 7 Fenchlorphos \ OQ [ í 0.768 8 Tolclofos-methyl \ OQ [ 0.698 9 Pirimiphos-methyl \ OQ [ í 0.781 10 ƍ ''( \ OQ [ í 0.748 11 Bromophos-ethyl \ OQ [ í 0.757 12 ƍ ''( \ OQ [ í 0.705 13 Procymidone \ OQ [ í 0.600 14 Picoxystrobin \ OQ [ í 0.740 15 Quinoxyfen \ OQ [ í 0.744 16 Chlorfenapyr \ OQ [ í 0.630 17 Benalaxyl \ OQ [ í 0.722 18 Bifenthrin \ OQ [ í 0.761 19 'LÀXIHQLFDQ \ OQ [ í 0.730 20 Bromopropylate \ OQ [ í 0.596 a 'HWHUPLQDWLRQ WLPH GD\ ZDV SORWWHG RQ WKH x -axis and the difference EHWZHHQ HDFK PHDVXUHG YDOXH DQG WKH ¿UVW WLPH PHDVXUHG YDOXH GHJUDGDWLRQ YDOXH RI WKH WDUJHW SHVWLFLGHV ZDV SORWWHG RQ WKH y -axis, DQG WKHQ WKH ORJDULWKPLF IXQFWLRQV ZHUH ¿WWHG

the deviation ratio accurately, the deviation ratio ranges of the pesticides were recalculated without the interval data of day 80 ( see Table 5). Among the above-mentioned remaining 14 pesticides, the deviation ratios were <15 , with most <10 , except for pirimicarb and bromophos-ethyl, which had the highest deviation ratios of 17.1 and 16.8 , respectively, and quinoxyfen and benalaxyl, which had the lowest deviation ratios of í24.3 and í16.0 , respectively. It is evident that the proposed method for predicting the residue concentrations of pesticides in aged Oolong tea in this study is accurate. The initial values of pesticides at c and d concns, together with their deviation ratios, are also listed in Table 5. It can be seen that the six pesticides with relatively higher deviation

Figure 10. Logarithmic chart of dimethenamid in aged Oolong tea. The determination times (days) were plotted on the x -axis, and WKH GLIIHUHQFHV EHWZHHQ HDFK PHDVXUHG YDOXH DQG WKH ¿UVW WLPH measured value (degradation value) of target pesticides were plotted on the y -axis.