An Optimized QuEChERS Workflow to Analyze Over 200 Pesticides in Honey
- QuEChERS can be modified to work with low-moisture, high-sugar commodities.
- Optimized workflow describes which products and procedures work best for this commodity.
- Over 98% of the 203 pesticides analyzed exhibit recoveries between 70-120%.
When it comes to the analysis of pesticide residues in low-moisture, high-sugar matrices, QuEChERS might not be the first sample preparation technique that comes to mind. QuEChERS is better known for its use in high-moisture fruits and vegetables, such as strawberries and spinach, with multiple official methods published for these types of commodities. However, QuEChERS is designed to achieve successful results with matrices that official methods may not cover, such as those low in moisture or high in sugars—it just needs to be modified.
Determining which QuEChERS products are most effective for commodities that extend beyond the scope of official methods can be problematic for food safety labs, which may not have experience with trialing different products and procedures. Similarly, the perception of the complexity involved may add an additional deterrent to labs looking to use this technique with other matrices.
In this article, we demonstrate an optimized workflow for the analysis of over 200 pesticides in honey that delivers acceptable results for this low-moisture, high-sugar commodity. We offer best practices for how to modify your sample preparation to optimize your current method and recommend several products that work best for this matrix.
Building on Our Preliminary Experiments
When we previously performed a QuEChERS extraction on low-moisture commodities using brown rice flour, we tested two approaches using the original unbuffered QuEChERS salts (cat.# 25847) to determine which would produce higher recoveries.
In the first approach, we added equal amounts of water and extraction solvent (10 mL) and kept the sample size the same (10 g). In the second approach, we added 10 mL of water and extraction solvent but cut the sample size in half (5 g). The sample matrix and water were shaken for 30 minutes before extraction. The methods were then tested with Restek’s QuEChERS performance mix (cat.# 31152), and the comparison is shown in Figure 1 for selected pesticides.
Figure 1: Comparison of selected pesticide's recoveries in brown rice flour with two different extraction methods.
While the raw recoveries (as area/area of internal standard) for most pesticides selected showed very little difference between the methods, DDT,p,p’- showed a significantly higher response with method 2. However, as brown rice flour has a fairly neutral pH and honey is more acidic, we wanted to see how another extraction salt, AOAC salts (cat.# 25851) performed when comparing the two methods for honey (Figure 2).
Figure 2: Method 1 (left tube) shows a much greater amount of sample solids and interferences, resulting in a small amount of extract. Method 2 (right tube), with its lower sample size, shows a reduced amount of sample solids and a greater amount of extract.
Given the higher response with method 2, we rehydrated our samples of honey using this method, and then evaluated different extraction salts and dSPE (Figures 3A & 3B).
Figure 3A: The evaluation of extraction salts showed that the more acidic environment of AOAC salts (cat.# 25851) resulted in higher recoveries, especially for dicofol.
Figure 3B: Due to the possible presence of sugars and waxes, the tested dSPE had either PSA (cat.# 26124) or C18-EC (cat. #26242) or a combination of both (cat.# 26125 and cat.# 26243) added. The best-performing dSPE tube was cat.# 26124 with 50 mg PSA.
It’s important to note that the best-performing dSPE for a given analysis will vary depending on which pesticides are most critical. For the pesticides featured in this article, we determined that the dSPE with 50 mg PSA (cat.# 26124) was most effective.
Applying Our Optimized Combination to 203 Analytes
Given the performance of our optimized combination of extraction salts and dSPE on a small number of analytes, we wanted to test against a larger group of pesticides. In this case, we spiked our honey samples using Restek’s GC multiresidue kit (cat.# 32562), which contains 203 compounds.
Chromatographic Method:
The chromatographic conditions were as follows. Retention times, ion transitions, and collision energies are provided in Appendix I.
Column: | Rxi-5ms, 30 m, 0.25 mm ID, 0.25 µm (cat.# 13423) | ||
Instrument: | GC-MS/MS | ||
Oven Program: | Temperature (°C) | Ramp Rate (°C/min) | Hold Time (min) |
90 | - | 1 | |
330 | @ 8 °C/min | 5 | |
Column Flow (constant): | 1.4 mL/min | ||
Injection Volume: | 1 µL | ||
Injection Type: | splitless, 0.5 min hold time | ||
Inlet Temperature: | 250 °C |
Outstanding Recoveries for Almost All Pesticides
When we look at the recoveries for this analysis, we can see that 201 out of the 203 compounds analyzed exhibit recoveries between 70-120% (Figure 3). Only two compounds, captafol (52%) and sulfotepp (120%) fell out of this range.
Figure 4: Almost all compounds had acceptable recoveries.
Conclusion
QuEChERS is a versatile technique that can work for an abundance of matrices—including those not covered by official methods. As shown, QuEChERS can easily be modified to be very effective for low-moisture, high-sugar matrices. By testing two methods to rehydrate our samples, then comparing extraction salts and dSPE options, we were able to create a highly successful workflow that achieved excellent recoveries for 201 analytes.
As the benefits of QuEChERS extractions include being quick, easy, and cheap, labs can utilize these advantages to modify their workflows to test against other matrices. While the official methods provide a great starting point, QuEChERS’ flexibility means it can be adaptable for the specific needs of each lab, even those testing more complicated commodities.
Appenidx I: Analyte MS transitions for spiked honey samples.
Analyte |
RT |
Quant Ion | Qual Ions | |||||||
Precursor Mass |
Product Mass |
Collision Energy |
Confirm Precursor |
Confirm Product |
Confirm Energy |
Confirm Precursor |
Confirm Product |
Confirm Energy |
||
2,4'-Methoxychlor |
20.24 |
227 |
121 |
12 |
121 |
78 |
20 |
121 |
91 |
12 |
2-Phenylphenol |
10.21 |
170 |
141 |
22 |
141 |
115 |
12 |
170 |
115 |
34 |
4,4'-Methoxychlor olefin |
19.75 |
308 |
223 |
30 |
238 |
152 |
35 |
238 |
195 |
20 |
Acequinocyl |
24.40 |
342 |
188 |
14 |
188 |
132 |
10 |
189 |
115 |
22 |
Acetochlor |
14.99 |
223 |
132 |
20 |
174 |
146 |
12 |
223 |
147 |
10 |
Acrinathrin |
22.47 |
289 |
93 |
10 |
181 |
152 |
26 |
208 |
181 |
10 |
Alachlor |
15.22 |
188 |
130 |
32 |
146 |
118 |
8 |
188 |
160 |
10 |
Aldrin |
16.04 |
298 |
263 |
8 |
263 |
191 |
35 |
263 |
193 |
31 |
Allidochlor |
6.90 |
138 |
81 |
8 |
132 |
56 |
6 |
138 |
96 |
8 |
Anthraquinone |
16.00 |
208 |
152 |
23 |
180 |
152 |
12 |
208 |
180 |
10 |
Atrazine |
13.30 |
215 |
173 |
8 |
200 |
122 |
10 |
200 |
132 |
10 |
Azinphos-ethyl |
22.53 |
160 |
77 |
18 |
132 |
77 |
12 |
160 |
132 |
6 |
Azinphos-methyl |
21.87 |
160 |
77 |
16 |
132 |
51 |
28 |
132 |
77 |
12 |
Benfluralin |
12.40 |
292 |
160 |
20 |
292 |
206 |
12 |
292 |
264 |
8 |
BHC, alpha- |
12.68 |
219 |
183 |
8 |
181 |
145 |
13 |
217 |
145 |
18 |
BHC, beta- |
13.33 |
219 |
183 |
8 |
181 |
109 |
27 |
181 |
145 |
15 |
BHC, delta- |
14.06 |
219 |
183 |
8 |
181 |
109 |
28 |
181 |
145 |
13 |
BHC, gamma- |
13.49 |
219 |
183 |
8 |
181 |
109 |
29 |
181 |
145 |
13 |
Bifenthrin |
21.12 |
181 |
165 |
25 |
165 |
115 |
30 |
181 |
166 |
10 |
Bioallethrin |
17.09 |
136 |
93 |
11 |
123 |
81 |
8 |
136 |
108 |
8 |
Biphenyl |
8.29 |
154 |
115 |
25 |
152 |
126 |
23 |
154 |
127 |
32 |
Bromfenvinphos |
18.00 |
325 |
269 |
10 |
267 |
159 |
15 |
323 |
267 |
10 |
Bromfenvinphos-methyl |
17.12 |
295 |
93 |
10 |
109 |
79 |
5 |
295 |
109 |
15 |
Bromophos methyl |
16.57 |
331 |
286 |
26 |
329 |
314 |
13 |
331 |
316 |
13 |
Bromophos-ethyl |
17.55 |
359 |
303 |
17 |
331 |
303 |
8 |
357 |
301 |
15 |
Bromopropylate |
21.08 |
341 |
183 |
15 |
183 |
155 |
12 |
341 |
185 |
13 |
Bupirimate |
18.56 |
316 |
208 |
8 |
273 |
108 |
16 |
273 |
193 |
8 |
Captafol |
20.75 |
313 |
197 |
30 |
79 |
51 |
22 |
79 |
77 |
12 |
Captan |
17.12 |
149 |
79 |
12 |
107 |
79 |
12 |
149 |
105 |
6 |
Carbophenothion |
19.69 |
342 |
157 |
10 |
125 |
97 |
6 |
199 |
143 |
10 |
Carfentrazone ethyl |
19.75 |
340 |
312 |
10 |
330 |
141 |
44 |
330 |
310 |
8 |
Chlorbenside |
17.35 |
268 |
125 |
8 |
125 |
89 |
17 |
125 |
99 |
19 |
Chlordane, cis- |
17.83 |
377 |
268 |
19 |
272 |
237 |
12 |
375 |
266 |
21 |
Chlordane, trans- |
17.48 |
375 |
266 |
18 |
272 |
237 |
13 |
373 |
264 |
18 |
Chlorfenapyr |
18.85 |
247 |
227 |
12 |
137 |
75 |
28 |
137 |
102 |
14 |
Chlorfenson |
17.95 |
302 |
175 |
8 |
175 |
111 |
8 |
177 |
113 |
8 |
Chlorfenvinphos |
17.13 |
323 |
267 |
10 |
267 |
159 |
15 |
295 |
267 |
5 |
Chlorobenzilate |
18.93 |
251 |
111 |
32 |
139 |
111 |
12 |
251 |
139 |
14 |
Chloroneb |
10.13 |
206 |
191 |
10 |
191 |
113 |
13 |
191 |
141 |
10 |
Chlorothalonil |
14.18 |
266 |
133 |
40 |
264 |
168 |
23 |
266 |
170 |
23 |
Chlorpropham |
12.02 |
213 |
171 |
8 |
127 |
65 |
22 |
171 |
127 |
8 |
Chlorpyrifos |
16.18 |
314 |
258 |
12 |
197 |
107 |
36 |
197 |
169 |
14 |
Chlorpyrifos-methyl |
15.04 |
286 |
93 |
22 |
286 |
208 |
12 |
286 |
241 |
24 |
Chlorthal-dimethyl |
16.29 |
332 |
301 |
8 |
299 |
221 |
24 |
301 |
223 |
24 |
Chlorthiophos |
19.37 |
325 |
269 |
14 |
269 |
205 |
15 |
297 |
269 |
8 |
Chlozolinate |
17.01 |
331 |
259 |
8 |
186 |
145 |
16 |
259 |
153 |
26 |
Clomazone |
13.33 |
204 |
107 |
18 |
125 |
89 |
13 |
125 |
99 |
17 |
Coumaphos |
23.28 |
362 |
109 |
17 |
210 |
182 |
10 |
362 |
226 |
13 |
Cycloate |
11.82 |
215 |
83 |
15 |
154 |
83 |
8 |
215 |
154 |
6 |
Cyfluthrin |
23.93 |
226 |
206 |
10 |
163 |
91 |
14 |
163 |
127 |
6 |
Cyhalothrin, lambda- |
22.26 |
208 |
181 |
8 |
181 |
152 |
23 |
197 |
141 |
10 |
Cypermethrin |
24.10 |
181 |
152 |
18 |
163 |
91 |
11 |
163 |
127 |
6 |
Cyprodinil |
16.74 |
225 |
210 |
12 |
224 |
118 |
34 |
224 |
208 |
20 |
DDD, o,p'- |
18.48 |
235 |
165 |
22 |
235 |
199 |
14 |
235 |
200 |
10 |
DDD, p,p'- |
19.20 |
237 |
165 |
22 |
235 |
165 |
24 |
235 |
199 |
12 |
DDE, o,p'- |
17.59 |
318 |
176 |
56 |
246 |
176 |
32 |
316 |
246 |
15 |
DDE, p,p'- |
18.29 |
318 |
248 |
22 |
246 |
176 |
28 |
316 |
246 |
20 |
DDT, o,p'- |
19.29 |
237 |
165 |
22 |
235 |
165 |
21 |
235 |
199 |
16 |
DDT, p,p'- |
20.01 |
237 |
165 |
22 |
235 |
165 |
21 |
235 |
199 |
16 |
Deltamethrin |
25.94 |
253 |
93 |
19 |
181 |
152 |
20 |
253 |
174 |
8 |
Diallate |
12.65 |
234 |
150 |
18 |
234 |
192 |
12 |
|||
Diazinon |
13.93 |
304 |
179 |
12 |
137 |
84 |
12 |
199 |
93 |
16 |
Dichlofluanid |
15.87 |
224 |
123 |
12 |
123 |
77 |
16 |
167 |
124 |
10 |
Dichloroaniline, 3,4'- |
9.00 |
163 |
90 |
16 |
161 |
99 |
21 |
161 |
126 |
8 |
Dichlorobenzophenone, 4,4'- |
16.23 |
139 |
75 |
27 |
111 |
75 |
12 |
139 |
111 |
13 |
Dichlobenil |
7.80 |
171 |
100 |
25 |
136 |
100 |
10 |
171 |
136 |
13 |
Dicloran |
12.96 |
206 |
148 |
18 |
176 |
148 |
10 |
206 |
176 |
10 |
Dieldrin |
18.35 |
279 |
243 |
10 |
263 |
193 |
34 |
277 |
241 |
8 |
Dimethachlor |
14.84 |
197 |
148 |
8 |
134 |
77 |
25 |
134 |
105 |
13 |
Diphenamid |
16.58 |
239 |
72 |
10 |
167 |
115 |
40 |
239 |
167 |
8 |
Diphenylamine |
11.64 |
169 |
167 |
25 |
167 |
166 |
17 |
169 |
168 |
12 |
Disulfoton |
14.02 |
153 |
97 |
12 |
88 |
60 |
6 |
142 |
109 |
6 |
Edifenphos |
19.80 |
310 |
109 |
29 |
109 |
65 |
13 |
173 |
109 |
8 |
Endosulfan ether |
14.53 |
272 |
237 |
10 |
239 |
204 |
13 |
241 |
206 |
13 |
Endosulfan I |
17.77 |
241 |
206 |
10 |
195 |
125 |
19 |
195 |
159 |
6 |
Endosulfan II |
18.97 |
241 |
206 |
10 |
195 |
125 |
23 |
195 |
159 |
8 |
Endosulfan sulfate |
19.87 |
274 |
239 |
12 |
241 |
206 |
8 |
272 |
237 |
10 |
Endrin |
18.84 |
279 |
243 |
8 |
245 |
173 |
25 |
263 |
193 |
30 |
Endrin aldehyde |
19.37 |
347 |
253 |
18 |
345 |
243 |
17 |
345 |
245 |
14 |
Endrin ketone |
20.96 |
317 |
101 |
21 |
315 |
279 |
8 |
317 |
281 |
8 |
EPN |
21.10 |
169 |
77 |
22 |
157 |
110 |
14 |
169 |
141 |
8 |
Ethalfluralin |
12.13 |
316 |
202 |
26 |
276 |
202 |
15 |
316 |
276 |
10 |
Ethion |
19.29 |
231 |
129 |
24 |
153 |
97 |
10 |
231 |
175 |
10 |
Ethylan |
18.83 |
223 |
167 |
12 |
223 |
179 |
22 |
223 |
193 |
28 |
Etofenprox |
24.38 |
163 |
77 |
34 |
163 |
107 |
18 |
163 |
135 |
10 |
Etridiazole |
9.28 |
211 |
140 |
22 |
183 |
140 |
16 |
211 |
183 |
10 |
Fenamiphos |
18.00 |
303 |
154 |
15 |
217 |
202 |
9 |
303 |
195 |
8 |
Fenarimol |
22.45 |
219 |
107 |
12 |
139 |
75 |
28 |
139 |
111 |
16 |
Fenchlorphos |
15.40 |
287 |
272 |
11 |
285 |
240 |
23 |
285 |
270 |
11 |
Fenitrothion |
15.68 |
277 |
109 |
16 |
260 |
125 |
12 |
277 |
260 |
8 |
Fenpropathrin |
21.26 |
265 |
210 |
8 |
181 |
127 |
24 |
181 |
152 |
24 |
Fenson |
16.43 |
268 |
77 |
18 |
141 |
77 |
8 |
268 |
141 |
8 |
Fenthion |
16.12 |
278 |
109 |
18 |
278 |
125 |
22 |
278 |
169 |
17 |
Fenvalerate |
25.34 |
225 |
119 |
15 |
167 |
125 |
8 |
169 |
127 |
10 |
Fipronil |
17.13 |
369 |
215 |
30 |
213 |
143 |
28 |
367 |
213 |
30 |
Fluazifop-P-butyl |
18.80 |
383 |
254 |
20 |
383 |
268 |
8 |
383 |
282 |
12 |
Fluchloralin |
14.01 |
306 |
160 |
20 |
264 |
160 |
15 |
306 |
264 |
8 |
Flucythrinate |
24.52 |
199 |
107 |
24 |
157 |
107 |
13 |
199 |
157 |
8 |
Fludioxonil |
18.20 |
248 |
127 |
30 |
154 |
127 |
8 |
248 |
154 |
20 |
Fluquinconazole |
23.28 |
340 |
108 |
42 |
340 |
298 |
14 |
340 |
313 |
12 |
Fluridone |
24.78 |
328 |
127 |
40 |
328 |
189 |
46 |
328 |
259 |
26 |
Flusilazole |
18.50 |
233 |
152 |
14 |
206 |
137 |
20 |
233 |
165 |
18 |
Flutolanil |
18.04 |
281 |
173 |
10 |
173 |
95 |
26 |
173 |
145 |
14 |
Flutriafol |
17.87 |
219 |
123 |
14 |
123 |
75 |
24 |
123 |
95 |
12 |
Folpet |
17.25 |
260 |
130 |
16 |
104 |
76 |
10 |
260 |
232 |
8 |
Fonofos |
13.70 |
246 |
109 |
16 |
137 |
109 |
6 |
246 |
137 |
8 |
Heptachlor |
15.23 |
272 |
237 |
13 |
100 |
65 |
12 |
270 |
235 |
13 |
Heptachlor epoxide |
16.95 |
353 |
263 |
13 |
263 |
193 |
29 |
351 |
261 |
11 |
Hexachlorobenzene |
12.87 |
284 |
214 |
30 |
249 |
214 |
14 |
284 |
249 |
18 |
Hexazinone |
20.21 |
171 |
71 |
16 |
128 |
83 |
10 |
171 |
85 |
16 |
Iodofenfos |
18.07 |
377 |
93 |
34 |
377 |
332 |
30 |
377 |
362 |
15 |
Iprodione |
20.85 |
314 |
245 |
14 |
187 |
124 |
24 |
314 |
271 |
12 |
Isazophos |
14.23 |
172 |
130 |
10 |
161 |
119 |
8 |
161 |
146 |
8 |
Isodrin |
16.71 |
261 |
191 |
28 |
193 |
123 |
30 |
193 |
157 |
19 |
Isopropalin |
16.73 |
280 |
118 |
25 |
280 |
180 |
10 |
280 |
238 |
8 |
Lenacil |
19.91 |
153 |
136 |
14 |
136 |
53 |
18 |
136 |
80 |
14 |
Leptophos |
21.91 |
377 |
269 |
37 |
171 |
77 |
18 |
171 |
124 |
8 |
Linuron |
15.76 |
248 |
61 |
8 |
160 |
133 |
11 |
187 |
124 |
21 |
Malathion |
15.92 |
173 |
99 |
13 |
127 |
99 |
6 |
173 |
127 |
6 |
Metalaxyl |
15.34 |
220 |
160 |
10 |
160 |
130 |
16 |
160 |
145 |
10 |
Metazachlor |
16.88 |
209 |
117 |
35 |
133 |
117 |
25 |
209 |
132 |
15 |
Methacrifos |
10.03 |
240 |
180 |
10 |
125 |
79 |
6 |
180 |
93 |
8 |
Methoxychlor |
21.14 |
227 |
115 |
50 |
227 |
141 |
33 |
227 |
169 |
25 |
Methyl parathion |
15.03 |
263 |
79 |
30 |
263 |
109 |
10 |
263 |
136 |
8 |
Metolachlor |
16.07 |
238 |
133 |
27 |
162 |
133 |
13 |
238 |
162 |
10 |
Mevinphos |
8.97 |
192 |
127 |
10 |
127 |
95 |
16 |
127 |
109 |
8 |
MGK 264 1 |
16.53 |
164 |
80 |
26 |
164 |
93 |
12 |
164 |
121 |
8 |
MGK 264 2 |
16.76 |
164 |
67 |
10 |
164 |
80 |
24 |
164 |
98 |
14 |
Mirex |
22.15 |
274 |
143 |
40 |
272 |
237 |
15 |
274 |
239 |
15 |
Myclobutanil |
18.43 |
179 |
90 |
28 |
179 |
125 |
14 |
179 |
152 |
8 |
N-(2,4-Dimethylphenyl)formamide |
9.67 |
121 |
106 |
8 |
106 |
77 |
15 |
120 |
77 |
15 |
Nitralin |
20.66 |
316 |
274 |
8 |
274 |
216 |
6 |
300 |
258 |
8 |
Nitrofen |
18.74 |
283 |
162 |
18 |
202 |
139 |
20 |
283 |
202 |
10 |
Nonachlor, cis- |
19.32 |
409 |
300 |
23 |
272 |
237 |
10 |
409 |
302 |
20 |
Nonachlor, trans- |
17.94 |
409 |
263 |
25 |
409 |
300 |
20 |
409 |
302 |
22 |
Norflurazon |
19.90 |
303 |
145 |
17 |
145 |
75 |
25 |
145 |
95 |
18 |
Oxadiazon |
18.36 |
258 |
175 |
8 |
175 |
112 |
13 |
175 |
147 |
8 |
Oxyfluorfen |
18.47 |
300 |
223 |
15 |
252 |
146 |
33 |
252 |
170 |
27 |
Paclobutrazol |
17.60 |
238 |
127 |
10 |
236 |
125 |
12 |
236 |
167 |
10 |
Parathion |
16.19 |
291 |
109 |
10 |
109 |
81 |
8 |
139 |
109 |
8 |
Pebulate |
9.40 |
203 |
128 |
8 |
128 |
57 |
8 |
161 |
128 |
6 |
Penconazole |
16.93 |
248 |
157 |
26 |
159 |
89 |
30 |
248 |
192 |
16 |
Pendimethalin |
16.91 |
281 |
252 |
8 |
252 |
162 |
10 |
252 |
191 |
8 |
Pentachloroaniline |
14.62 |
265 |
107 |
46 |
263 |
192 |
20 |
265 |
194 |
22 |
Pentachloroanisole |
12.99 |
280 |
237 |
23 |
265 |
237 |
12 |
267 |
239 |
10 |
Pentachlorobenzene |
10.35 |
250 |
142 |
30 |
250 |
179 |
30 |
250 |
215 |
20 |
Pentachlorobenzonitrile |
13.66 |
275 |
205 |
30 |
273 |
177 |
25 |
273 |
238 |
17 |
Pentachlorothioanisole |
15.81 |
298 |
265 |
8 |
296 |
246 |
32 |
296 |
263 |
12 |
Permethrin, cis- |
23.01 |
183 |
153 |
12 |
163 |
127 |
6 |
183 |
168 |
10 |
Permethrin, trans- |
23.16 |
183 |
153 |
14 |
163 |
91 |
13 |
163 |
127 |
6 |
Phenothrin |
21.68 |
183 |
153 |
14 |
123 |
81 |
8 |
183 |
168 |
12 |
Phorate |
12.56 |
260 |
75 |
8 |
121 |
65 |
10 |
121 |
93 |
6 |
Phosalone |
21.86 |
367 |
111 |
36 |
182 |
75 |
30 |
182 |
111 |
14 |
Phosmet |
21.03 |
160 |
77 |
24 |
160 |
133 |
10 |
160 |
160 |
8 |
Piperonyl butoxide |
20.46 |
176 |
103 |
26 |
176 |
117 |
20 |
176 |
131 |
14 |
Pirimiphos-ethyl |
16.67 |
333 |
168 |
22 |
304 |
168 |
12 |
318 |
166 |
12 |
Pirimiphos-methyl |
15.72 |
305 |
180 |
8 |
290 |
125 |
22 |
290 |
233 |
14 |
Pretilachlor |
18.26 |
262 |
202 |
8 |
162 |
117 |
30 |
162 |
132 |
18 |
Prochloraz |
23.35 |
308 |
70 |
13 |
180 |
69 |
15 |
180 |
138 |
12 |
Procymidone |
17.31 |
283 |
67 |
28 |
283 |
96 |
10 |
283 |
255 |
12 |
Prodiamine |
15.73 |
321 |
216 |
15 |
279 |
203 |
8 |
321 |
279 |
6 |
Profenofos |
18.19 |
339 |
188 |
30 |
337 |
267 |
13 |
339 |
269 |
13 |
Profluralin |
13.71 |
330 |
69 |
25 |
318 |
199 |
17 |
318 |
264 |
8 |
Propachlor |
11.53 |
176 |
57 |
8 |
120 |
77 |
19 |
120 |
92 |
8 |
Propanil |
14.78 |
219 |
163 |
8 |
161 |
99 |
25 |
217 |
161 |
8 |
Propargite |
20.31 |
201 |
81 |
10 |
135 |
77 |
24 |
135 |
107 |
14 |
Propisochlor |
15.32 |
223 |
132 |
18 |
162 |
120 |
13 |
162 |
144 |
10 |
Propyzamide |
13.70 |
173 |
74 |
46 |
173 |
109 |
27 |
173 |
145 |
13 |
Prothiofos |
18.13 |
309 |
239 |
15 |
267 |
221 |
16 |
267 |
239 |
8 |
Pyraclofos |
22.69 |
360 |
139 |
14 |
194 |
138 |
18 |
360 |
194 |
10 |
Pyrazophos |
22.54 |
265 |
210 |
10 |
221 |
193 |
10 |
232 |
204 |
10 |
Pyridaben |
23.17 |
147 |
117 |
20 |
147 |
119 |
8 |
147 |
132 |
13 |
Pyridaphenthion |
20.95 |
340 |
199 |
8 |
199 |
77 |
26 |
199 |
92 |
14 |
Pyrimethanil |
13.81 |
198 |
118 |
32 |
198 |
158 |
20 |
198 |
183 |
16 |
Pyriproxyfen |
21.94 |
226 |
186 |
16 |
136 |
78 |
20 |
136 |
96 |
12 |
Quinalphos |
17.17 |
298 |
156 |
8 |
146 |
118 |
10 |
156 |
155 |
14 |
Quintozene |
13.62 |
295 |
237 |
15 |
235 |
141 |
26 |
237 |
119 |
22 |
Resmethrin |
20.44 |
171 |
128 |
15 |
123 |
81 |
8 |
171 |
143 |
6 |
Sulfotepp |
12.50 |
322 |
146 |
23 |
202 |
146 |
10 |
322 |
202 |
10 |
Sulprofos |
19.55 |
322 |
97 |
24 |
156 |
141 |
13 |
322 |
156 |
8 |
Tau-Fluvalinate |
25.35 |
252 |
55 |
17 |
250 |
55 |
23 |
250 |
200 |
19 |
Tebuconazole |
20.29 |
250 |
125 |
22 |
125 |
89 |
16 |
250 |
153 |
12 |
Tebufenpyrad |
21.36 |
333 |
276 |
8 |
276 |
171 |
10 |
318 |
131 |
13 |
Tecnazene |
11.45 |
261 |
203 |
13 |
215 |
144 |
22 |
215 |
179 |
8 |
Tefluthrin |
14.19 |
197 |
161 |
6 |
177 |
127 |
15 |
177 |
137 |
15 |
Terbacil |
14.10 |
161 |
88 |
22 |
160 |
117 |
8 |
161 |
144 |
14 |
Terbufos |
13.62 |
231 |
129 |
23 |
231 |
175 |
12 |
231 |
203 |
8 |
Terbutylazine |
13.61 |
229 |
138 |
12 |
173 |
138 |
8 |
229 |
173 |
8 |
Tetrachloroaniline, 2,3,5,6- |
11.72 |
231 |
122 |
30 |
231 |
158 |
20 |
231 |
160 |
22 |
Tetrachlorvinphos |
17.71 |
333 |
109 |
17 |
331 |
79 |
30 |
331 |
109 |
20 |
Tetradifon |
21.66 |
227 |
199 |
10 |
159 |
111 |
20 |
159 |
131 |
10 |
Tetrahydrophthalimide |
9.67 |
151 |
77 |
32 |
151 |
80 |
6 |
151 |
122 |
10 |
Tetramethrin |
21.11 |
164 |
77 |
25 |
164 |
107 |
12 |
164 |
135 |
8 |
Tolclofos-methyl |
15.14 |
267 |
252 |
10 |
265 |
93 |
25 |
265 |
250 |
10 |
Tolylfluanid |
17.04 |
240 |
137 |
10 |
137 |
91 |
17 |
238 |
137 |
10 |
Transfluthrin |
15.14 |
163 |
91 |
12 |
127 |
91 |
8 |
163 |
143 |
13 |
Triadimefon |
16.24 |
208 |
111 |
24 |
208 |
127 |
14 |
208 |
181 |
10 |
Triadimenol |
17.18 |
168 |
70 |
10 |
112 |
58 |
10 |
128 |
65 |
22 |
Triallate |
14.24 |
270 |
186 |
18 |
268 |
184 |
20 |
268 |
226 |
10 |
Triazophos |
19.55 |
257 |
162 |
8 |
161 |
106 |
12 |
161 |
134 |
8 |
Tricyclazole |
18.20 |
189 |
118 |
20 |
189 |
135 |
18 |
189 |
162 |
12 |
Triflumizole |
17.37 |
206 |
179 |
14 |
179 |
144 |
14 |
206 |
186 |
10 |
Trifluralin |
12.35 |
306 |
160 |
23 |
306 |
206 |
12 |
306 |
264 |
8 |
Triphenylphosphate |
20.35 |
326 |
169 |
30 |
326 |
215 |
20 |
|||
Vinclozolin |
15.03 |
285 |
212 |
12 |
212 |
145 |
24 |
212 |
172 |
12 |