Table 4
Range stratified comparison of diaminoatrazine, ELISA vs. GC. N=74
GC Conc. Range         Number of       Number of ELISA     Number of ELISA
(number of samples    ELISA results in  results Under GC     results over GC
in GC range)          GC range             range               range
0-1.0ppb (61)            51                                     10
1.1 -2.Oppb (8)                                                  8
2.1 - 3.0 ppb (5)                                                 5
>3.0 ppb (0)                                                    11
Table 5
Range stratified comparison of the sum of ELISA diaminoatrazine & atrazine
compared with GC total atrazine 1. N=74
GC Conc. Range            Number of        Number of ELISA        Number of
(number of samples in  ELISA results in   results below GC      ELISA results
GC conc. range         same GC range            range          above GC range
0-1.0ppb (47)                43                                      4
1.1 -2.0ppb (8)              5                   1                   2
2.1 - 3.0ppb (7)             4                   3
>3.Oppb (12)                 11                  1
1. Total atrazine = atrazine+diaminoatrazine+desethylatrazine+deisopropylatrazine
Table 6
Comparison of data stratified above and below the 3.0 ppb MCL N=74
GC and ELISA  GC <3.0 and  GC >3.0 and  GC and ELISA
results both  ELISA >3.0  ELISA <3.0  results both
ELISA            GC          <3.0 ppb  "over estimate" . "under    >3.0 ppb
analytes        analytes     (agreement)               estimate" ".agreement"
Diaminoatrazine  Diaminoatrazine   66           8            0            0
Diaminoatrazine + Diaminoatrazine +  63          7            0           4
Atrazine        Atrazine
Diaminoatrazine +  Total Atrazine 1  62          0            1           11
Atrazine
Atrazine     Total Atrazine 1   62           0            12           0
Diaminoatrazine  Total Atrazine 1  61           1            1           11

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