IJCA - Volume 3 - Flipbook - Page 17
15
2024 | Volume 3, Issue 1
near the greenhouse wall. Here, in addition to the
effect of the reversing area of the spraying machine,
there are possible rebound effects from the wall,
which can also in昀氀uence the residue concentration.
In contrast to the passed test of the sampling plan,
the analytical test failed for the laboratory uncertainty
(UL), but passed for the expanded uncertainty (UE)
(Table 2).
Table 2. Assessment (F = failed, P = passed) of the test
for the residue concentration c (mg/kg) for expanded
uncertainty UE and laboratory uncertainty UL
ANALYTE
Chlormequat
C (MG/KG)
CR
CT
1.0
1.3
ASSESSED FOR
UE
UL
P
F
Case 2: The reference sampling was an area-covering
“W” with 12 sampling points. The test sampling was
set to three equidistant “ladders” with four equidistant
sampling points each. The new plan should reduce
the sampling time because fewer rows have to be
committed. For UE and UL, the analytical test failed,
indicating objective reasons (Table 3).
Table 3. Assessment (F = failed, P = passed) of the test
for the residue concentration c (mg/kg) for expanded
uncertainty UE and laboratory uncertainty UL
ANALYTE
Chlorantraniliprol
Cyprodinil
Pyridalyl
C (MG/KG)
CR
CT
0.330 0.094
0.016 0.014
0.670
0.04
ASSESSED FOR
UE
UL
F
F
P
P
F
F
Case 4: Four packs of 500g each were taken from
the total. The reference sample was taken from four
different colli stacks, but the test sample was only
taken from three stacks (one stack sampled twice).
The test sampling protocol passed. The analytical
results also passed within the uncertainty of 50%, but
taking only the laboratory measurement uncertainty
of 25% as a basis, the test would have to be rated as
failed (Table 5).
Table 5. Assessed test (F = failed, P = passed) for the
residue concentrations c (mg/kg) of the reference
(CR) and test (CT) sample for expanded uncertainty
UE (± 50%) and laboratory uncertainty UL (± 25%)
ANALYTE
Mandipropamid
Spirotetramat-enol
Spirotetramat
-enol-glucosid
Spirotetramat Sum
Difenoconazol
Dithiocarbamate
Phosphonic acid
Fosetyl-Al
C (MG/KG)
CR
CT
0.025
0.01
0.026 0.029
0.091
0.1
0.11
0.01
0.01
3.4
4.5
0.12
0.012
0.018
8.5
11.4
ASSESSED FOR
UE
UL
P
F
P
P
P
P
P
P
P
P
P
P
P
F
F
F
Case 5: A historical sewage 昀椀eld with areas of
distinctly different lead and copper concentrations, but
relatively stable distribution was used for technician
authorisation. Exposed areas should be identi昀椀ed from
a technical description and excluded from sampling.
Case 3: The aim of the trial was as in Case 2 but the
number of sampling point has been increased to
30 and the number of ladders to 6. It seems that an
increase in ladders and/or sampling points improves
the consistency of the sampling methods with
regards to the analytical result (Table 4).
The sampling plans matched except of the selected
areas. The test sample also included exposed areas
whereas the reference did not.
Table 4. Assessment (F = failed, P = passed) of the test
for the residue concentration c (mg/kg) for expanded
uncertainty UE and laboratory uncertainty UL
Table 6. Assessed test (F = failed, P = passed) for the
residue concentrations c (mg/kg) of the reference
(CR) and test (CT) sample for expanded uncertainty
UE (± 50%) and laboratory uncertainty UL (± 25%)
ANALYTE
Boscalid
Pyraclostrobin
Pyriproxyfen
Abamectin Sum
Fluopyram Sum
C (MG/KG)
CR
CT
0.071 0.057
0.015 0.016
0.010 0.010
0.010 0.010
0.010 0.010
ASSESSED FOR
UE
UL
P
P
P
P
P
P
P
P
P
P
The test of the analytical result passed despite the
differences in the sampling plan (Table 6). The reason
could be a dilution effect.
ANALYTE
UE
Copper
Cadmium
Mercury
Lead
C (MG/KG)
CR
CT
37.3
26.6
2.92
2.16
1.24
0.93
60.09 68.16
ASSESSED FOR
UE
UL
P
P
P
P
P
P
P
P
