Analysis of Pesticides and their Metabolite Residues in Plant-Based Food by LC-MS/MS acc. to GB 23200.121-2021

Jack Wang
R&D APAC lab, Shanghai, China

 

Abstract

According to the GB 23200.121-2021 standard, a method for the simultaneous determination of pesticides (331) and their 44 metabolites in plant-based food by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established. After QuEChERS sample preparation and purification using Supel™ QuE Citrate Extraction Tube & Supel™ QuE PSA/ENVI-Carb Cleanup Tube, an LC-MS/MS setup using a 2 µm particle Purospher^® STAR RP-18 endcapped UHPLC column was utilized for analysis. Quantitation was performed using an external matrix-matched standard calibration. All pesticide residues displayed an excellent linearity in the concentration range from 0.01 to 0.2 mg/L, and the correlation coefficients R² were greater than 0.9950. The recoveries were 67.2% to 108%, relative standard deviations were ranging from 3.5% to 8.5%, and the limit of quantitation (LOQ) was <10 μg/kg for all compounds. The method can be used for the detection and analysis of 331 pesticide residues and their 44 metabolites in plant-based food according to the GB method with high accuracy and reliability.

Overview of Sections:

• Introduction
• Experimental
  
• Results & Discussion
• Conclusion

Introduction

Pesticide residues in fruits and vegetables can pose a threat to the health of consumers. Hence, it is desirable to keep the level of pesticide residues in plant-based food as low as possible and make sure they are not exceeding given maximum residue levels (MRLs). To ensure this, frequent monitoring of those levels is required to ensure the consumer's health. With this background, a simple and quick sample preparation technology was introduced with the QuEChERS method (Quick, Easy, Cheap, Effective, Rugged, Safe) which was developed in the early 2000s by Anastassiades and Lehotay¹ and it became the main sample preparation method for pesticide determination in food. It was formalized in official methods such as AOAC 2007.01 and EN 15662.

In 2018 and 2021, the China Administration for Market Regulation issued GB 23200.113-2018,"Determination of 208 Pesticides and their Metabolites Residues in Plant-derived Foods by Gas chromatography-Mass spectrometry”² and GB 23200.121-2021 “Determination of 331 Pesticides and their Metabolite Residues in Plant-Based Food by LC-MS/MS”³.These two national standards describe the QuEChERS principle for the sample preparation for the first time in official GB methods, which got since vigorously promoted and used.

The GB standard 23200.121-2021 specifies the analysis parameters for the determination of pesticides and pesticide metabolite residues in plant-based food for 23 sample matrices. With a single injection analysis, 331 pesticides and 44 metabolites (in total 375 compounds) can be monitored, including highly toxic and prohibited organophosphorus and carbamate pesticides as well as commonly sold pesticide varieties such as triazole fungicides and benzoyl urea pesticides (Table 7).

In this application, using cabbage as a sample, a method is presented following the GB standard 23200.121-2021 and employing Supel™ Que Citrate Extraction Tubes and Supel™ Que PSA/Envi-Carb Clean up Tubes for the QuEChERS sample preparation and a Purospher^® STAR RP-18 endcapped (2 µm) UHPLC column for the LC-MS/MS analysis. The method is evaluated against the criteria stated in the GB standard.

Experimental

The pre-treatment method in this experiment (QuEChERS) and the use of a matrix-matched external calibration were in accordance with what is described in the GB 23200.121-2021 standard. The following procedures were applied:

Standard, Sample, and Reagent Preparation

Analyzed Samples

• Weigh 500 g of cabbage, chop and mix thoroughly. Sample by the quartering method or homogenize in a tissue masher, and store in polyethylene bottles. One is the sample is to be analyzed, another is used retention sample. The samples were stored at -18℃ and the retention period was 3 months.
• Sample blank solution: The used cabbage sample was prepared according to the sample preparation specified in GB 23200.121-2021 and tested according to the method by LC-MS/MS. The result showed that none of the target compounds could be detected in the sample.

Reagent Preparation

• Extraction solvent: Add 10 mL acetic acid to 990 mL acetonitrile and mix well to obtain a solution of 1% acetic acid in acetonitrile (1:99, v:v).
• Mobile phase [A]: Weigh 0.1261 g ammonium formate, dissolve in an aqueous solution of 0.01% formic acid, and dilute to 1000 mL to obtain a solution of 2 mmol/L (2 mM) ammonium formate/formic acid in water.
• Mobile phase [B]: Weigh 0.1261 g ammonium formate, dissolve with 0.01% formic acid methanol solution, and dilute to 1000 mL, to obtain a solution of 2 mmol/L (2 mM) ammonium formate/formic acid in methanol.

Standard Preparation

• Pesticide Standard Stock Mixture: A mix of the 331 pesticides and their 44 metabolites in methanol with a concentration of 100 µg/mL each is used for standard preparation.
• Pesticide stock solution I (10 µg/mL): Transfer 1 mL of a standard stock mixture of 331 pesticides and their 44 metabolites (concentration: 100 µg/mL) into a 10 mL amber glass volumetric flask and fill up to the mark with ethyl acetate. Store the standard solution at 0 °C - 4 °C and protected from light.
• Pesticide stock solution II (1.00 µg/mL): Pipette 1 mL of pesticide stock solution I into a 10 mL amber glass volumetric flask and fill up to the mark with ethyl acetate to obtain a pesticide stock solution II with a pesticide/metabolite concentration of 1.00 µg/mL each. Store at 0 °C – 4 °C and protected from light.
• Pesticide standard solutions 1-5: Prepare a total of five standard working solutions (nos. 1-5) by pipetting 2 μL, 5 μL, 10 μL, 50 μL, and 200 μL of pesticide stock solution II into five separate 2 mL vials. Add matrix blank solution (cabbage blank extract) with a pipette to get to a final volume of 1 mL. The concentrations of the pesticides in the resulting solutions are 2.0, 5.0, 10.0, 50.0, and 200 μg/L, respectively.

Sample Preparation:

• Extraction: Weigh 10 g of a homogenized cabbage sample into a 50 mL plastic centrifuge tube, and add 10 mL 1% acetic acid in acetonitrile, the content of one Supel™ QuE citrate extraction tube (55227-U, containing 4 g magnesium sulfate, 1 g sodium chloride, 1 g trisodium citrate, and 0.5 g disodium hydrogen citrate) and one ceramic milling ball. Shake the centrifuge tube vigorously for 1 min, then centrifuge at 4200 rpm for 5 min.
  Add 6 mL of the supernatant to a 15 mL PSA/ENVI-Carb tube (Supel™ QuE QuEChERS PSA/ENVI-Carb Tube 1, 55446-U, containing 15 mg Supelclean™ ENVI-Carb, 150 mg Supelclean™ PSA, and 900 mg magnesium sulfate), vortex, and mix for 1 min. Centrifuge at 4200 rpm for 5 minutes and filter the resulting solution using a 0.22 μm microporous filtration membrane.
• Spiking experiments: For the determination of method recovery (%) and precision, prepare two samples by mixing 10.0 g of vegetable sample with 500 μL and 1000 μL of pesticide stock solution II, respectively. The concentrations of the pesticides in the two samples are 50 µg/kg (utilized for the analysis of precision) and 100 µg/kg (used for recovery).

Instruments and Equipment

• ANPEL EUFO-945416 vortex mixer
• Eppendorf 5810R centrifuge, speed ≥ 10000 rpm
• Mettler Toledo ME204T/02 electronic balances, sensitivity 0.01 mg and 0.01 g, respectively
• IKA T-18 high-speed homogenizer

LC-MS Analysis

Table 1. Conditions used for pesticide analysis by HPLC according to GB23200.121-2021

LC Conditions
Instrument:	Waters™ Acquity I-class plus and Waters™ Xevo TQS
Column:	Purospher® STAR RP-18 endcapped (2 µm) Hibar® HR 100-2.1 (1.50648)
Mobile phase:	[A] Ammonium formate (2 mM), 0.01% formic acid in water [B] Ammonium formate (2 mM) - 0.01% formic acid in methanol
Gradient:	Time (min)	% A	% B
	0	97	3
	1.0	97	3
	1.5	85	15
	2.5	50	50
	18	30	70
	23	2	98
	27	2	98
	27.1	97	3
	30	97	3
Flow rate:	0.30 mL/min
Pressure:	178.5 bar
Column temp:	30 °C
Detector:	MS/MS, MRM, ESI pos./neg. (see Table 2)
Injection:	2.0 μL
Samples:	Cabbage extracts and matrix-matched standards (see above)

Table 2. MS conditions used for pesticide analysis

MS Conditions
MS Instrument:	Waters™ Xevo TQS UPS
Capillary voltage:	4.0 kV
Atomization gas flow:	3.0 mL/min
Heater flow:	10.0 mL/min
Heat block temperature:	400 °C
DL tube temperature:	250 °C
Interface temperature:	300 °C
Ionization mode:	ESI pos./neg.
Scan:	Multiple reaction monitoring (MRM) – transitions used and retention data, see Table in appendix

Results and Discussion

Separation

Cabbage samples were prepared by QuEChERS and then analyzed by HPLC-MS/MS, with the mass spectrometer being operated in MRM mode. Determination of pesticide residues and pesticide metabolites was performed using an external matrix-matched calibration. The developed method was applied for the analysis of 331 pesticide residues and 44 metabolites (see the full list in Table 7) and compared to the requirements of the GB Standard regarding calibration linearity, precision, recovery, and sensitivity.

Calibration data

The results of the calibration experiments utilizing pesticide standard solutions 1-5 are displayed in Figure 1 and Table 3. for avermectin as an example pesticide, all other compounds provided similar results. The linearity (R²) ranged from 0.9953 to 0.9999, meeting the GB 23200.121-2021 requirement of >0.9950.

Table 3. Calibration data obtained for avermectin using pesticide standard solutions 1-5 (c = 2.0, 5.0, 10.0, 50.0 and 200 μg/L).

Sample	Avermectin concentration (μg/L)	Area
Pesticide Standard solution 1	2.0	1161
Pesticide Standard solution 2	5.0	2998
Pesticide Standard solution 3	10.0	5905
Pesticide Standard solution 4	50.0	30105
Pesticide Standard solution 5	200	107890

Data Precision and Recovery (%)

The cabbage sample with a pesticide spike concentration of 50 µg/kg was used for precision evaluation, while the second sample (pesticide spike concentration 100 µg/kg) was utilized for the evaluation of recovery. Results obtained for three pesticides as examples are shown in Tables 4 and 5 below. The precision for all analytes ranged between 3.5% and 8.5% RSD meeting the GB 23200.121-2021 criteria of <15%. Analyte recoveries for all compounds were determined to be between 67% and 108%, lying in the GB 23200.121-2021 specified range of 60-120%.

For the sensitivity determination the baseline noise of a blank cabbage sample was employed. The resulting limit of quantification (LOQ) was <10 µg/kg for the 331 pesticides and their 44 metabolites (Table 6)

Table 4 Precision (RSD) of the method at a pesticide concentration of 50 µg/kg in the cabbage sample for avermectin, acephate and acetamiprid as examples, data for all other pesticides and metabolites was comparable

Precision (RSD)	Avermectin (µg/kg)	Acephate (µg/kg)	Acetamiprid (µg/kg)
Theoretical value	50.0	50.0	50.0
Measured value 1	43.2	44.9	43.9
Measured value 2	44.1	43.9	42.2
Measured value 3	45.5	42.5	46.7
Measured value 4	43.8	46.1	47.1
Measured value 5	42.0	45.3	46.5
Measured value 6	41.9	44.4	45.9
Measured value 7	44.4	42.1	44.9
Average	43.6	44.2	45.8
RSD (%)	3.0	3.3	2.7

Table 5. % Recovery of the method at a pesticide concentration of 100 µg/kg in the vegetable sample. Results for avermectin, acephate and acetamiprid as examples, data for all other pesticides and metabolites was comparable

Recovery	Avermectin (%)	Acephate (%)	Acetamiprid (%)
Injection 1	78.9	94.9	104
Injection 2	76.6	90.5	102
Injection 3	75.9	87.8	104
Injection 4	84.3	89.9	101
Injection 5	80.7	89.1	99.7
Injection 6	79.3	90.8	100
Average	79.3	90.5	101.8

Summary Suitability Criteria

In Table 6 a summarized overview on the suitability criteria of the GB method and the determined values is provided, showing that the developed method complies with the GB 23200.121-2021 requirements.

Table 6. Overview of GB Method criteria and the presented method

Parameter	GB 23200.121-2021 Criteria	Determined value ranges
Linearity (2.0-200 µg/L) R2	>0.9950	0.9953 to 0.9999
Reproducibility (RSD)	<15%	3.5% to 8.5%
Recovery	60-120%	67.2% to 108%
LOQ	<10 µg/kg	<10 µg/kg

Real sample measurements

Table 7 provides the full compound listing for this study.

Table 7. Compound listing of pesticides and their metabolites covered in this study

Comp. No.	Compound Name	Comp. No.	Compound Name	Comp. No.	Compound Name	Comp. No.	Compound Name
2	Acephate	84	Dimoxystrobin	167	Iprodione	248-1	Prochloraz
3	Acetamiprid	85	Diniconazole	168-1	Iprovalicarb-1	248-2	Prochloraz-metabolite BTS44595
4	Acetochlor	86	Dinocap	168-2	Iprovalicarb-2	248-3	Prochloraz-metabolite BTS44596
5	Alachlor	87	Dinotefuran	169	Isazofos	249	Procymidone
6	Albendazole	88-4	Disulfoton sulfone	170	Isocarbophos	250	Profenofos
7-1	Aldicarb	88-5	Disulfoton sulfoxide	171	Isofenphos-methyl	251	Promecarb
7-2	Aldicarb sulfone	88-1	Disulfoton-1	172	Isoprocarb	252	Prometryn
7-3	Aldicarb sulfoxid	89	Diuron	173	Isoprothiolane	253	Propachlor
8	Ametoctradin	90	Edifenphos	174	Isoproturon	254	Propamocarb
9	Ametryn	91	Emamectin benzoate	175-1	Isopyrazam-1	255	Propanil
10	Amidosulfuron	92	Enestroburin	175-2	Isopyrazam-2	256	Propaquizafop
11	Amisulbrom	93	EPN	176-1	Isoxaflutole	257	Propargite
12	Anilofos	94	Epoxiconazole	176-2	Isoxaflutole- diketonitrile	258	Propieonazole
13	Atrazine	95	Ethion	177	Ivermectin	259	Propisochlor
1	Avermectin	96	Ethiprole	178	Kresoxim-methyl	260	Propoxur
14	Azinphos-methyl	97	Ethirimol	179	Lactofen	261	Propyrisulfuron
15	Azoxystrobin	98	Ethofumcsale	180	Linuron	262	Propyzamide
17	Benazolin-ethyl	99	Ethoprophos	181	Lufenuron	263	Proquinazid
18	Bendiocarb	100	Ethoxysulfuron	182-2	Malaoxon	264	Prosulfocarb
19	Bensolfuron methyl	101	Etofenprox	182-1	Malathion	265	Pyraclostrobin
20	Benzovindiflupyr	102	Etoxazole	183	Mandipropamid	266	Pyraflufen-ethyl
21	Benzoximate	103	Etrimfos	184	Mefenacet	267	Pyrametostrobin
22	Bifenox	104	Famoxadone	185	Mepronil	268	Pyraoxystrobin
23	Bifenthrin	105	Fenamidone	186	Mesosulfuron- methyl	269	Pyrazosulfuron-ethyl
24	Biorcsmethrin	106	Fenaminstrobin	187	Metaflumizone	270-1	Pyrethrin-1
25-1	Bitertanol-1	107-1	Fenamiphos	188	Metalaxyl	270-2	Pyrethrin-2
25-2	Bitertanol-2	107-2	Fenamiphos sulfone	189	Metamifop	271	Pyribenzoxim
16	Bonalaxyl	107-3	Fenamiphos sulfoxide	190	Metamitron	272	Pyridaben
26	Boscalid	108	Fenarimol	191	Metazachlor	273	Pyridalyl
27-1	Bromuconazole-1	109	Fenazaquim	192	Metazosulfuron	274	Pyridaphenthion
27-2	Bromuconazole-2	110	Fenbuconazole	193	Metconazole	275	Pyriftalid
28	Bupirimate	111	Fenhexamid	194-1	Methacrifos-1	276	Pyrimethanil
29	Buprofezin	112	Fenobucarb	194-2	Methacrifos-2	277	Pyrimorph
30	Butachlor	113	Fenothiocarb	195	Methamidophos	278	Pyriproxyfen
31	Butralin	114-1	Fenoxanil-1	196	Methidathion	279-1	Pyrisoxazole-1
32	Cadusafos	114-2	Fenoxanil-2	197-1	Methiocarb	279-2	Pyrisoxazole-2
33	Carbaryl	115	Fenoxaprop-ethyl	197-2	Methiocarb sulfone	280	Quinalphos
34	Carbendazim	116	Fenoxycarb	197-3	Methiocarb sulfoxide	281	Quizalofop-ethyl
35-1	Carbofuran	117	Fenpropathrin	198	Methomyl	282	Rotenone
35-2	3-Hydroxy Carbofuran	118	Fenpropidin	199	Methoprene	283	Saflufenacil
36	Carboxin	119	Fenpropimorph	200	Methoxyfenozide	284-1	Sedaxane-1
37	Carfentrazone-ethyl	120	Fenpyrazamine	201	Metolachlor	284-2	Sedaxane-2
38	Chlorantraniliprole	121	Fenpyroximate	202	Metolcarb	285	Sethoxydim
39	Chlorbenzuron	122-1	Fensulfothion	203	Metrafenone	286	Silthiofam
40	Chlordimeform	122-2	Fensulfothion oxon	204	Metrilbuzin	287	Simazine
41-1	Chlorfenvinphos-1	122-3	Fensulfothion oxon sulfone	205	Metsulfuron-methyl	288	Simetryn
41-2	Chlorfenvinphos-2	122-4	Fensulfothion sulfone	206-1	Mevinphos-1	289-2	Spinetoram I
42	Chlorfluazuron	123-1	Fenthion	206-2	Mevinphos-2	289-1	Spinetoram J
43	Chloridazon	123-2	Fenthion sulfone	207	Molinate	290-1	Spinosad A
44	Chlorimuron-ethyl	123-3	Fenthion sulfoxide	208	Monocrotophos	290-1	Spinosad D
45	Chlorpropham	124	Fenvalerate	209	Myclobutanil	291	Spirodiclofen
46	Chlorpyrifos	125-1	Fipronil	210	Napropamide	292	Spiromesifon
47	Chlorpyrifos-methyl	125-2	Fipronil deulfinyl	211	Nitenpyram	293-1	Spirotramat
48	Chlorsulfuron	125-3	Fipronil silfide	212	Novaluron	293-2	Spirotramat-enol
49	Chlortoluron	125-4	Fipronil sulfone	213	Omethoate	293-3	Spirotramat-enol- glucoside
50	Chromafenozide	126	Flonicamid	214	Ortbosulfamuron	293-4	Spirotramat-keto- hydroxy
51	Cinosulfuron	127	Florasulam	215	Oxadiargyl	293-5	Spirotramat-mono- hydroxy
52-1	Clethodim	128	Fluazifop-butyl	216	Oxadiazon	294	Sulfentrazone
52-2	Clethodim sulfone	129	Fluazinam	217	Oxadixyl	295	Sulfotep
52-3	Clethodim sulfoxide	130	Flubendiamide	218-2	Oxamy oxime	296	Sulfoxaflor
53	Clofentezine	131-1	Flucetosulfuron-1	218-1	Oxamyl	297	Tau-fluvalinate
54	Clomazone	131-2	Flucetosulfuron-2	219	Oxaziclomefone	298	Tebnconazole
55	Clothianidin	132	Flucythrinate	220-1	Oxydemeton-methyl	299	Tebufenozide
56	Coumaphos	133	Fludioxonil	221	Oxyfluorfen	300	Tebuthiuron
57	Coumoxystrobin	134	Flufenacet	222-1	Paclobutrazol-1	301	Teflubenzuron
58	Cyanazine	135	Flufenoxuron	222-2	Paclobutrazol-2	302-1	Terbufos
59	Cyantraniliprole	136	Flumetralin	223	Parathion	302-2	Terbufos sulfone
60-1	Cyazofamid	137	Flumetsulam	224	Penconazole	302-3	Terbufos sulfoxide
60-2	Cyazofamid metabolite	138	Flumorph	225	Pencycuron	303	Terbuthylazine
61	Cyclosulfamuron	139	Fluopicolide	226	Pendimethalin	304	Tetraconazole
62	Cycloxydim	140	Fluopyram	227	Penflufen	305	Thiabendazole
63	Cyflufenamid	141	Fluoroglycofen-ethyl	228	Penoxsulam	306	Thiacloprid
64	Cyflumetofen	142	Flurtamone	229	Penthiopyrad	307	Thiamethoxam
65	Cymoxanil	143	Flusilazole	230-1	Permethrin-1	308	Thidiazuron
66	Cyproconazole	144	Fluthiacet-methyl	230-2	Permethrin-2	309	Thifensulfuron-methyl
67	Cyprodinil	145	Flutolanil	231	Phenamacril	310	Thifluzamide
68	Deltamethrin	146	Flutriafol	232	Phenmedipham	311	Thiophanate-methyl
69	Demeton	147	Fluxapyroxad	233	Phenthoate	312	Tolclofos-methyl
220-2	Demeton-S-methyl	148	Fonofos	234-1	Phorate	313	Tolfenpyrad
220-3	Demeton-S-methyl- sulfone	149	Forchlorfenuron	234-2	Phorate sulfone	314	Tralkoxydim
88-2	Demeton-S-sulfone	150	Formothion	234-3	Phorate sulfoxide	315	Triadimefon
88-3	Demeton-S-sulfoxide	151	Fosthiazate	235	Phosalone	316	Triadimenol
70	Diazinon	152	Furathiocarb	236	Phosfolan	317	Triallate
71	Dichlorvos	153	Halosulfuron-methyl	237	Phosfolan-methyl	318	Triasulfuron
72	Diclobutrazol	154	Heptenophos	238-1	Phosmet	319	Triazophos
73	Diclofop-methyl	155	Hexaconazole	238-2	Phosmet oxon	320	Tribenuron-methyl
74	Dicrotophos	156	Hexaflumuron	239-1	Phosphamidon-1	321	Triclorfon
75	Dicthofencarb	157	Hexazinone	239-2	Phosphamidon-2	322	Tricyclazole
76	Diethyl aminocthyl hexanoate	158	Hexythiazox	240	Phoxim	324-2	Triflumizde metabolite FM-6-1
77-1	Difenoconazole-1	159	Imazalil	241	Picolinafen	324-1	Triflumizole
77-2	Difenoconazole-2	160	Imibenconazole	242	Picoxystrobin	323	Triflumizole
78	Diflubenzuron	161	Imidacloprid	243	Piperonyl butoxide	325	Triflumuron
79	Diflufenican	162	Imidaclthiz	244-1	Pirimicarb	326	Triflusulfuron-methyl
80	Dimepiperate	163	Indoxacarb	244-2	Pirimicarb-desmethyl	327	Triticonazole
81	Dimethenamid	164	Iodosulfuron-methyl-s odium	244-3	Pirimicarb-desmethyl- formamido	328	Tritosulfuron
82	Dimethoate	165-1	Ipconazole-1	245	Pirimophos-methyl	329	Uniconazole
83-1	Dimethomorph-1	165-2	Ipconazole-2	246	Pretilachlor	330	Vamidothion
83-2	Dimethomorph-2	166	Iprobenfos	247	Probenazole	331	Zoxamide

Conclusion

The new GB 23200.121-2021 is the first national standard in China that combines QuEChERS sample preparation with LC-MS/MS analysis for the determination of multiple residues in complex samples such as plant-derived food (23 sample matrices covered). In this work, a set of 331 pesticides and 44 metabolites were analyzed in a cabbage sample according to the GB standard using Supel™ QuE QuEChERS mixes for extraction and sample cleanup and a Purospher^® STAR RP-18 endcapped (2 µm) UHPLC column for analysis by LC-MS/MS employing dynamic MRM.

Quantitation was performed using an external matrix-matched standard calibration. The presented method complied with the quality criteria defined the GB standard regarding linearity, reproducibility, recovery, and limit of quantification (LOQ). All pesticide residues displayed an excellent linearity in the concentration range from 0.01 to 0.2 mg/L, with correlation coefficients R2 greater than 0.9950 as required by the GB method. The recoveries were 67.2% to 108% (GB criteria: 60-120%), relative standard deviations were ranging from 3.5-8.5% (GB criteria: <20%), and the LOQ was <10 μg/kg for all investigated compounds. 

The shown method can therefore be used for the detection and analysis of pesticide residues and their metabolites in plant food acc. to GB 23200.121-2021 with high accuracy and reliability.

Find more applications on Food & Beverage Testing.

REFERENCES

1. Anastassiades M, Lehotay SJ, Štajnbaher D, Schenck FJ. 2003. Fast and Easy Multiresidue Method Employing Acetonitrile Extraction/Partitioning and “Dispersive Solid-Phase Extraction” for the Determination of Pesticide Residues in Produce. J AOAC Int. 86(2):412-431. https://doi.org/10.1093/jaoac/86.2.412

2. GB 23200.113-2018, "Determination of 208 pesticides and their metabolites residues in plant-derived foods by gas chromatography-mass spectrometry". [Internet]. Available from: http://down.foodmate.net/standard/yulan.php?itemid=53165

3. GB 23200.121-2021, “determination of 331 pesticides and their metabolites residues in plant-derived food by liquid chromatography-mass spectrometry”. . [Internet]. Available from: http://down.foodmate.net/standard/yulan.php?itemid=97823

Appendix Table: MRM & RT Data

Compound no.	Compound name	Retention time (min)	Detected mass m/z
2	Acephate	3.03	184.0 ->143.0
3	Acetamiprid	4.06	223.1 ->126.0
4	Acetochlor	13.93	270.1 ->224.1
5	Alachlor	14.02	270.1 ->238.1
6	Albendazole	9.96	266.1 ->234.1
7-1	Aldicarb	4.87	208.1 ->116.1
7-2	Aldicarb sulfone	3.40	240.1 ->148.0
7-3	Aldicarb sulfoxid	3.29	207.1 ->132.0
8	Ametoctradin	19.24	276.2 ->176.1
9	Ametryn	9.62	228.1 ->186.1
10	Amidosulfuron	6.04	370.0 ->261.0
11	Amisulbrom	20.50	466.0 ->227.0
12	Anilofos	16.99	368.0 ->199.0
13	Atrazine	7.69	216.1 ->174.0
1	Avermectin	23.44	895.5 ->751.4
14	Azinphos-methyl	9.19	318.0 ->132.0
15	Azoxystrobin	10.60	404.1 ->372.1
17	Benazolin-ethyl	9.90	272.0 ->198.0
18	Bendiocarb	5.70	224.1 ->167.0
19	Bensolfuron methyl	9.61	411.1 ->149.1
20	Benzovindiflupyr	16.78	396.0 ->368.0
21	Benzoximate	18.60	364.1 ->199.0
22	Bifenox	18.89	359.0 ->310.0
23	Bifenthrin	23.69	440.2 ->181.1
24	Biorcsmethrin	23.17	339.2 ->171.1
25-1	Bitertanol-1	18.34	338.2 ->269.2
25-2	Bitertanol-2	18.62	338.2 ->269.2
16	Bonalaxyl	17.5	326.2 ->148.1
26	Boscalid	11.20	343.0 ->307.1
27-1	Bromuconazole-1	12.56	378.0->159.0
27-2	Bromuconazole-2	15.03	378.0->159.0
28	Bupirimate	15.07	317.2 ->166.1
29	Buprofezin	21.43	306.2 ->201.1
30	Butachlor	21.61	312.2 ->238.1
31	Butralin	22.37	296.2 ->240.1
32	Cadusafos	19.60	271.1 ->159.0
33	Carbaryl	6.25	202.1 ->145.1
34	Carbendazim	4.10	192.1 ->160.1
35-1	Carbofuran	5.83	222.1 ->165.1
35-2	3-Hydroxy Carbofuran	4.05	238.1 ->181.1
36	Carboxin	6.36	236.1 ->143.0
37	Carfentrazone-ethyl	16.37	412.0 ->346.1
38	Chlorantraniliprole	9.49	484.0 ->452.9
39	Chlorbenzuron	15.90	309.0 ->156.0
40	Chlordimeform	3.66	197.1 ->117.1
41-1	Chlorfenvinphos-1	17.53	359.0 ->155.0
41-2	Chlorfenvinphos-2	18.42	359.0 ->155.0
42	Chlorfluazuron	22.66	540.0 ->382.9
43	Chloridazon	4.21	222.0 ->104.0
44	Chlorimuron-ethyl	11.58	415.0 ->186.0
45	Chlorpropham	11.54	214.1 ->172.0
46	Chlorpyrifos	21.77	349.9 ->197.9
47	Chlorpyrifos-methyl	18.65	321.9 ->125.1
48	Chlorsulfuron	5.87	358.0 ->167.1
49	Chlortoluron	7.18	213.1 ->72.0
50	Chromafenozide	14.18	395.2 ->175.1
51	Cinosulfuron	5.14	414.1 ->183.1
52-1	Clethodim	20.57	360.1 ->164.1
52-2	Clethodim sulfone	8.56	392.1 ->300.1
52-3	Clethodim sulfoxide	8.79	376.1 ->206.1
53	Clofentezine	17.87	303.0 ->138.0
54	Clomazone	9.26	240.1 ->125.0
55	Clothianidin	3.91	250.0 ->169.1
56	Coumaphos	11.57	363.0 ->227.0
57	Coumoxystrobin	21.72	437.2 ->145.1
58	Cyanazine	5.31	241.1 ->214.1
59	Cyantraniliprole	6.77	475.0 ->285.9
60-1	Cyazofamid	14.36	325.1 ->108.0
60-2	Cyazofamid metabolite	11.98	216.0 ->179.0
61	Cyclosulfamuron	13.43	422.1 ->261.0
62	Cycloxydim	20.41	326.2 ->280.1
63	Cyflufenamid	19.17	413.1 ->295.1
64	Cyflumetofen	21.18	465.2 ->173.0
65	Cymoxanil	4.39	199.1 ->128.0
66	Cyproconazole	12.72	292.1 ->125.0
67	Cyprodinil	15.28	226.1 ->93.1
68	Deltamethrin	22.81	523.0 ->280.9
69	Demeton	9.60	259.1 ->89.0
220-2	Demeton-S-methyl	5.99	231.0 ->89.0
220-3	Demeton-S-methyl-sulfone	3.57	263.0 ->169.0
88-2	Demeton-S-sulfone	4.28	291.0 ->235.0
088-3	Demeton-S-sulfoxide	4.17	275.1 ->197.0
70	Diazinon	17.36	305.1 ->169.0
71	Dichlorvos	5.57	221.0 ->109.0
72	Diclobutrazol	15.93	328.1 ->70.0
73	Diclofop-methyl	21.08	358.0 ->281.0
74	Dicrotophos	3.72	238.1 ->112.1
75	Dicthofencarb	10.29	268.2 ->226.1
76	Diethyl aminocthyl hexanoate	4.05	216.2 ->143.1
77-1	Difenoconazole-1	19.28	406.1 ->251.0
77-2	Difenoconazole-2	19.30	406.1 ->251.0
78	Diflubenzuron	14.64	311.0 ->158.0
79	Diflufenican	20.11	395.1 ->266.0
80	Dimepiperate	19.63	264.1 ->146.1
81	Dimethenamid	10.82	276.1 ->244.1
82	Dimethoate	4.13	230.0 ->199.0
83-1	Dimethomorph-1	10.75	388.1 ->301.1
83-2	Dimethomorph-2	11.68	388.1 ->301.1
84	Dimoxystrobin	15.58	327.2 ->205.1
85	Diniconazole	18.57	326.1 ->70.0
86	Dinocap	22.16	295.1 ->209.0
87	Dinotefuran	3.31	203.1 ->129.1
88-4	Disulfoton sulfone	7.45	307.0 ->153.0
88-5	Disulfoton sulfoxide	7.16	291.0 ->185.0
88-1	Disulfoton-1	18.56	275.0 ->89.0
89	Diuron	8.12	233.0 ->72.0
90	Edifenphos	16.77	311.0 ->283.0
91	Emamectin benzoate	21.62	886.5 ->82.1
92	Enestroburin	21.24	400.1 ->178.0
93	EPN	19.58	324.0 ->157.0
94	Epoxiconazole	14.22	330.1 ->121.0
95	Ethion	21.73	385.0 ->199.0
96	Ethiprole	11.06	397.0 ->351.0
97	Ethirimol	6.32	210.2 ->140.1
98	Ethofumcsale	10.22	287.1 ->259.1
99	Ethoprophos	13.78	243.1 ->97.0
100	Ethoxysulfuron	12.00	399.1 ->261.0
101	Etofenprox	23.64	394.2 ->177.1
102	Etoxazole	22.35	360.2 ->141.0
103	Etrimfos	16.19	293.1 ->265.0
104	Famoxadone	17.84	392.2 ->331.1
105	Fenamidone	10.79	312.1 ->92.0
106	Fenaminstrobin	20.64	434.1 ->171.0
107-1	Fenamiphos	15.20	304.1 ->217.0
107-2	Fenamiphos sulfone	6.16	336.1 ->308.1
107-3	Fenamiphos sulfoxide	5.88	320.1 ->233.0
108	Fenarimol	13.34	331.0 ->268.1
109	Fenazaquim	22.97	307.2 ->161.1
110	Fenbuconazole	14.66	337.1 ->125.0
111	Fenhexamid	13.38	302.1 ->97.1
112	Fenobucarb	9.72	208.1 ->95.0
113	Fenothiocarb	14.89	254.1 ->72.0
114-1	Fenoxanil-1	15.09	329.1 ->302.1
114-2	Fenoxanil-2	15.48	329.1 ->302.1
115	Fenoxaprop-ethyl	20.89	362.1 ->288.0
116	Fenoxycarb	15.15	302.1 ->116.1
117	Fenpropathrin	22.43	350.2 ->125.1
118	Fenpropidin	8.28	274.3 ->147.1
119	Fenpropimorph	12.39	304.3 ->147.1
120	Fenpyrazamine	12.89	332.1 ->304.1
121	Fenpyroximate	22.64	422.2 ->366.1
122-1	Fensulfothion	8.02	309.0 ->281.0
122-2	Fensulfothion oxon	4.54	293.1 ->237.0
122-3	Fensulfothion oxon sulfone	4.67	309.1->253.0
122-4	Fensulfothion sulfone	8.49	325.0 ->269.0
123-1	Fenthion	16.14	279.1 ->169.0
123-2	Fenthion sulfone	6.53	311.0 ->124.8
123-3	Fenthion sulfoxide	6.10	295.0 ->280.0
124	Fenvalerate	22.96	437.2 ->167.1
125-1	Fipronil	15.76	434.9 ->330.0
125-2	Fipronil deulfinyl	14.78	387.0 ->351.0
125-3	Fipronil silfide	16.61	418.9 ->262.0
125-4	Fipronil sulfone	17.83	450.9 ->414.9
126	Flonicamid	3.60	230.1 ->203.0
127	Florasulam	4.55	360.0 ->129.0
128	Fluazifop-butyl	21.31	384.1 ->282.0
129	Fluazinam	21.55	462.9 ->415.9
130	Flubendiamide	17.34	705.0 ->531.0
131-1	Flucetosulfuron-1	9.26	488.1 ->156.1
131-2	Flucetosulfuron-2	9.92	488.1 ->156.1
132	Flucythrinate	22.27	469.2->412.0
133	Fludioxonil	10.71	266.1 ->229.0
134	Flufenacet	13.91	364.1 ->194.1
135	Flufenoxuron	22.28	489.0 ->158.0
136	Flumetralin	22.33	422.1 ->143.0
137	Flumetsulam	3.87	326.1 ->129.0
138	Flumorph	8.78	372.2 ->285.1
139	Fluopicolide	11.87	383.0 ->173.0
140	Fluopyram	13.37	397.1 ->208.0
141	Fluoroglycofen-ethyl	20.66	465.1->344.0
142	Flurtamone	10.51	334.1 ->247.1
143	Flusilazole	15.14	316.1 ->247.1
144	Fluthiacet-methyl	15.95	404.0 ->274.0
145	Flutolanil	11.85	324.1 ->262.1
146	Flutriafol	7.58	302.1 ->123.0
147	Fluxapyroxad	11.91	382.1 ->362.1
148	Fonofos	16.43	247.0 ->109.0
149	Forchlorfenuron	8.24	248.1 ->129.0
150	Formothion	5.05	258.0 ->199.0
151	Fosthiazate	7.02	284.1 ->228.0
152	Furathiocarb	21.36	383.2 ->195.0
153	Halosulfuron-methyl	10.98	435.0 ->182.1
154	Heptenophos	8.29	251.0->127.0
155	Hexaconazole	17.10	314.1 ->70.0
156	Hexaflumuron	20.67	461.0->158.0
157	Hexazinone	5.89	253.2 ->171.1
158	Hexythiazox	21.88	353.1 ->228.0
159	Imazalil	7.83	297.1->159.0
160	Imibenconazole	21.38	411.0 ->125.0
161	Imidacloprid	3.83	256.1 ->175.1
162	Imidaclthiz	3.95	262.0 ->181.1
163	Indoxacarb	20.33	528.1 ->293.0
164	Iodosulfuron-methyl-sodium	8.23	508.0 ->167.1
165-1	Ipconazole-1	19.78	334.2 ->70.0
165-2	Ipconazole-2	20.26	334.2 ->70.0
166	Iprobenfos	16.07	289.1 ->205.0
167	Iprodione	14.56	330.0 ->245.0
168-1	Iprovalicarb-1	13.63	321.2 ->119.1
168-2	Iprovalicarb-2	13.81	321.2 ->119.1
169	Isazofos	12.95	316.0->164.0
170	Isocarbophos	8.25	231.0 ->121.0
171	Isofenphos-methyl	16.67	332.1 ->121.0
172	Isoprocarb	7.48	194.1 ->95.0
173	Isoprothiolane	11.76	291.1 ->231.0
174	Isoproturon	7.90	207.1 ->72.0
175-1	Isopyrazam-1	19.42	360.2 ->244.1
175-2	Isopyrazam-2	19.67	360.2 ->244.1
176-1	Isoxaflutole	8.21	360.0 ->251.0
176-2	Isoxaflutole-diketonitrile	4.73	358.0 ->79.0
177	Ivermectin	24.15	897.5 ->753.4
178	Kresoxim-methyl	15.84	314.1 ->267.1
179	Lactofen	21.48	479.1 ->344.0
180	Linuron	9.87	249.0 ->160.0
181	Lufenuron	21.89	511.0 ->158.0
182-2	Malaoxon	5.93	315.1 ->127.0
182-1	Malathion	11.98	331.0 ->127.0
183	Mandipropamid	11.81	412.1 ->328.1
184	Mefenacet	12.59	299.1->148.1
185	Mepronil	11.99	270.1 ->228.1
186	Mesosulfuron-methyl	7.51	504.1 ->182.1
187	Metaflumizone	21.56	507.1 ->178.0
188	Metalaxyl	8.27	280.2 ->220.1
189	Metamifop	21.18	441.1 ->288.0
190	Metamitron	4.15	203.1 ->175.1
191	Metazachlor	7.93	278.1 ->210.1
192	Metazosulfuron	8.87	476.1 ->182.1
193	Metconazole	17.72	320.2 ->70.0
194-1	Methacrifos-1	7.47	241.0 ->209.0
194-2	Methacrifos-2	8.83	241.0 ->209.0
195	Methamidophos	2.85	142.0 ->94.0
196	Methidathion	8.74	303.0 ->145.0
197-1	Methiocarb	10.23	226.1 ->169.1
197-2	Methiocarb sulfone	4.12	258.1 ->201.1
197-3	Methiocarb sulfoxide	3.90	242.1->185.1
198	Methomyl	3.58	163.1 ->88.0
199	Methoprene	23.38	279.0 ->191.0
200	Methoxyfenozide	12.79	369.2 ->149.1
201	Metolachlor	14.46	284.1 ->252.1
202	Metolcarb	5.18	166.1 ->109.1
203	Metrafenone	18.97	409.1 ->209.1
204	Metrilbuzin	5.88	215.1 ->187.1
205	Metsulfuron-methyl	5.46	382.1 ->167.1
206-1	Mevinphos-1	4.05	225.1 ->127.0
206-2	Mevinphos-2	4.46	225.1 ->127.0
207	Molinate	11.69	188.1 ->126.1
208	Monocrotophos	3.63	224.1 ->98.1
209	Myclobutanil	12.12	289.1 ->70.0
210	Napropamide	13.90	272.2 ->129.1
211	Nitenpyram	3.46	271.1 ->225.1
212	Novaluron	21.03	493.0 ->158.1
213	Omethoate	3.22	214.0 ->183.0
214	Ortbosulfamuron	8.13	425.1 ->199.1
215	Oxadiargyl	18.18	341.0 ->223.0
216	Oxadiazon	21.54	345.1 ->303.0
217	Oxadixyl	4.98	279.1 ->249.1
218-2	Oxamy oxime	3.23	163.1 ->72.0
218-1	Oxamyl	3.42	237.1 ->72.0
219	Oxaziclomefone	21.05	376.1 ->190.1
220-1	Oxydemeton-methyl	3.49	247.0 ->169.0
221	Oxyfluorfen	20.89	362.0 ->316.0
222-1	Paclobutrazol-1	11.54	294.1 ->70.0
222-2	Paclobutrazol-2	11.89	294.1 ->70.0
223	Parathion	15.34	292.0 ->236.0
224	Penconazole	15.76	284.0->159.0
225	Pencycuron	19.09	329.1 ->125.0
226	Pendimethalin	21.85	282.1 ->212.1
227	Penflufen	16.07	318.2 ->234.1
228	Penoxsulam	6.54	484.1 ->195.1
229	Penthiopyrad	16.69	360.1 ->276.0
230-1	Permethrin-1	23.23	408.1 ->183.1
230-2	Permethrin-2	24.47	408.1 ->183.1
231	Phenamacril	5.41	217.1 ->104.0
232	Phenmedipham	9.26	301.1 ->168.1
233	Phenthoate	15.89	321.0 ->79.1
234-1	Phorate	17.65	261.0 ->75.0
234-2	Phorate sulfone	7.5	293.0 ->97.0
234-3	Phorate sulfoxide	7.17	277.0 ->199.0
235	Phosalone	18.41	368.0 ->182.0
236	Phosfolan	4.67	256.0 ->140.0
237	Phosfolan-methyl	3.68	228.0 ->168.0
238-1	Phosmet	9.43	318.0 ->160.0
238-2	Phosmet oxon	4.90	302.0 ->160.0
239-1	Phosphamidon-1	5.03	300.1 ->174.1
239-2	Phosphamidon-2	5.22	300.1 ->174.1
240	Phoxim	17.99	299.1 ->129.0
241	Picolinafen	21.37	377.1 ->238.0
242	Picoxystrobin	15.69	368.1 ->205.1
243	Piperonyl butoxide	21.63	356.2 ->177.1
244-1	Pirimicarb	6.81	239.2 ->182.1
244-2	Pirimicarb-desmethyl	4.52	225.1 ->168.1
244-3	Pirimicarb-desmethyl-formamido	5.73	253.0 ->72.0
245	Pirimophos-methyl	18.31	306.1 ->164.1
246	Pretilachlor	20.42	312.2 ->252.1
247	Probenazole	5.24	224.0 ->41.0
248-1	Prochloraz	17.93	376.2 ->308.0
248-2	Prochloraz-metabolite BTS44595	17.04	325.0 ->282.0
248-3	Prochloraz-metabolite BTS44596	16.72	353.0 ->308.0
249	Procymidone	12.98	284.0 ->256.0
250	Profenofos	20.70	372.9 ->302.9
251	Promecarb	10.90	208.1 ->151.1
252	Prometryn	12.55	242.1 ->158.0
253	Propachlor	7.97	212.1 ->170.0
254	Propamocarb	3.20	189.2 ->102.1
255	Propanil	9.97	218.0 ->162.0
256	Propaquizafop	21.43	444.1 ->371.1
257	Propargite	22.28	368.2 ->231.2
258	Propieonazole	16.92	342.1 ->159.0
259	Propisochlor	16.69	284.1 ->224.1
260	Propoxur	5.72	210.1 ->111.0
261	Propyrisulfuron	12.41	456.1 ->196.1
262	Propyzamide	11.45	256.0 ->190.0
263	Proquinazid	22.62	373.0 ->331.0
264	Prosulfocarb	20.30	252.1 ->128.1
265	Pyraclostrobin	18.23	388.1 ->194.1
266	Pyraflufen-ethyl	17.41	413.0 ->339.0
267	Pyrametostrobin	16.24	382.2 ->194.1
268	Pyraoxystrobin	18.65	413.1 ->205.1
269	Pyrazosulfuron-ethyl	12.48	415.1 ->182.1
270-1	Pyrethrin-1	22.46	329.2 ->161.1
270-2	Pyrethrin-2	20.47	329.2 ->161.1
271	Pyribenzoxim	21.75	610.2 ->413.1
272	Pyridaben	22.98	365.1 ->309.1
273	Pyridalyl	24.05	492.0 ->109.0
274	Pyridaphenthion	12.71	341.1 ->189.1
275	Pyriftalid	9.65	319.0 ->139.0
276	Pyrimethanil	9.83	200.1 ->183.1
277	Pyrimorph	17.42	385.2 ->242.0
278	Pyriproxyfen	21.60	322.1->96.0
279-1	Pyrisoxazole-1	10.77	289.1 ->151.1
279-2	Pyrisoxazole-2	11.83	289.1 ->151.1
280	Quinalphos	15.55	299.1 ->163.0
281	Quizalofop-ethyl	20.87	373.1 ->299.1
282	Rotenone	15.05	395.1 ->213.1
283	Saflufenacil	10.30	501.1 ->459.0
284-1	Sedaxane-1	12.70	332.2 ->159.0
284-2	Sedaxane-2	14.17	332.2 ->159.0
285	Sethoxydim	24.26	328.2->178.1
286	Silthiofam	15.78	268.1 ->252.1
287	Simazine	5.88	202.1 ->124.1
288	Simetryn	7.24	214.1 ->124.1
289-2	Spinetoram I	21.95	760.5 ->142.1
289-1	Spinetoram J	20.94	748.5 ->142.1
290-1	Spinosad A	19.57	732.5 ->142.1
290-1	Spinosad D	20.69	746.5 ->142.1
291	Spirodiclofen	22.75	411.1 ->313.0
292	Spiromesifon	22.37	388.0->273.0
293-1	Spirotramat	13.98	374.2->302.2
293-2	Spirotramat-enol	7.10	302.2 ->270.1
293-3	Spirotramat-enol-glucoside	3.74	464.2 ->216.1
293-4	Spirotramat-keto-hydroxy	8.76	318.2 ->300.2
293-5	Spirotramat-mono-hydroxy	5.72	304.2 ->254.2
294	Sulfentrazone	6.19	387.0 ->307.0
295	Sulfotep	16.52	323.0->171.0
296	Sulfoxaflor	4.19	278.1 ->174.1
297	Tau-fluvalinate	23.16	503.1 ->208.1
298	Tebnconazole	16.35	308.2->70.0
299	Tebufenozide	15.88	353.2 ->133.1
300	Tebuthiuron	6.15	229.1 ->172.1
301	Teflubenzuron	21.26	381.0 ->158.0
302-1	Terbufos	21.15	289.1 ->103.1
302-2	Terbufos sulfone	10.16	321.0 ->97.0
302-3	Terbufos sulfoxide	10.19	305.0 ->187.0
303	Terbuthylazine	10.80	230.1 ->174.1
304	Tetraconazole	13.85	372.0 ->159.0
305	Thiabendazole	4.57	202.0 ->175.0
306	Thiacloprid	4.33	253.0 ->126.0
307	Thiamethoxam	3.58	292.0 ->211.1
308	Thidiazuron	5.73	221.0 ->102.0
309	Thifensulfuron-methyl	5.24	388.0 ->167.1
310	Thifluzamide	14.83	528.8 ->148.0
311	Thiophanate-methyl	5.62	343.1 ->151.0
312	Tolclofos-methyl	17.81	301.0 ->268.9
313	Tolfenpyrad	21.48	384.1 ->197.1
314	Tralkoxydim	21.94	330.2 ->284.2
315	Triadimefon	12.20	294.1 ->197.1
316	Triadimenol	12.71	296.1 ->70.0
317	Triallate	21.84	304.0 ->143.0
318	Triasulfuron	5.38	402.1 ->167.0
319	Triazophos	12.88	314.1->197.1
320	Tribenuron-methyl	7.78	396.1 ->155.1
321	Triclorfon	4.15	256.9 ->109.0
322	Tricyclazole	4.67	190.0 ->163.0
324-2	Triflumizde metabolite FM-6-1	5.36	295.0 ->215.0
324-1	Triflumizole	20.23	346.1 ->278.1
323	Triflumizole	20.35	409.1 ->186.1
325	Triflumuron	18.44	359.0 ->139.0
326	Triflusulfuron-methyl	12.04	493.1 ->264.1
327	Triticonazole	13.69	318.1 ->70.0
328	Tritosulfuron	7.69	446.0 ->195.0
329	Uniconazole	14.54	292.1 ->70.0
330	Vamidothion	4.00	288.0 ->146.1
331	Zoxamide	16.86	336.0 ->187.0