Systems and Methods for Pesticide Detection

Abstract

This disclosure provides quantitative, rapid, and reliable LC-MS/MS methods for analyzing panels of pesticides and mycotoxins in various samples, including very hydrophobic and chlorinated compounds normally analyzed on a GC-MS/MS system. The methods can be carried out using a single instrument and can detect and quantify levels of the pesticides and mycotoxins that are well below action limits specified by U.S. states (e.g., California) and other countries (e.g., Canada) for these compounds in cannabis products.

1 . A method of detecting a pesticide in a sample, the method comprising:
 (a) ionizing at least a portion of the sample using an atmospheric chemical ionization (APCI) source to create a first ionized sample stream; and   (b) detecting, using a triple quadrupole mass spectrometer, a first MRM transition in the first ionized sample stream, wherein the first MRM transition is selected from the group consisting of 439.8>35.1 (chlordane) and 441.8>35.1 (chlordane).   
     
     
         2 . The method of  claim 1 , further comprising:
 (c) ionizing at least a portion of the sample using an electrospray ionization (ESI) source to create a second ionized sample stream; and   (d) detecting a second MRM transition in the second ionized sample stream.   
     
     
         3 . The method of  claim 2 , wherein the second MRM transition is an MRM transition of a pesticide, wherein the pesticide is selected from the group consisting of abamectin, acephate, acequinocyl, acetamiprid, aldicarb, atrazine, azoxystrobin, bifenazate, bifenthrin, boscalid, captan, carbaryl, carbofuran, chlorantraniliprole, chlorfenapyr, chlorpyrifos, cinerin-I, cinerin-II, clofentezine, coumaphos, cyfluthrin, cypermethrin, daminozide, diazinon, dichlorvos, dimethoate, dimethomorph, ethoprophos, etofenprox, etoxazole, fenhexamid, fenoxycarb, fenpyroximate, fipronil, flonicamid, fludioxonil, hexythiazox, imazalil, imidacloprid, jasmolin-I, jasmolin-II, kresoxim-methyl, malathion, metalaxyl, methiocarb, methomyl, mevinphos, myclobutanil, naled, n-octyl bicycloheptene dicarboximide (MGK-264), oxamyl, paclobutrazol, parathion methyl, permethrin, phosmet, piperonyl butoxide, prallethrin, propiconazole, propoxur, pyrethrin-I, pyrethrin-II, pyridaben, spinetoram, spinosyn A, spinosyn D, spiromesifen, spirotetramat, spiroxamine, tebuconazole, thiachloprid, thiamethoxam, thiophanate methyl, and trifloxystrobin. 
     
     
         4 . The method of  claim 1 , wherein the first ionized sample stream is obtained from a cannabis sample. 
     
     
         5 . The method of  claim 2 , further comprising:
 (e) detecting a third MRM transition in the second ionized sample stream, wherein the third MRM transition is associated with a mycotoxin selected from the group consisting of mycotoxin B1, mycotoxin B2, mycotoxin G1, mycotoxin G2, and ochratoxin A.   
     
     
         6 . The method of  claim 3 , further comprising:
 (e) detecting a third MRM transition in the second ionized sample stream, wherein the third MRM transition is associated with a mycotoxin selected from the group consisting of mycotoxin B1, mycotoxin B2, mycotoxin G1, mycotoxin G2, and ochratoxin A.   
     
     
         7 . The method of  claim 2 , wherein the second MRM transition is selected from the group consisting of 402.2>343.1 (acequinocyl) and 402.2>189 (acequinocyl). 
     
     
         8 . The method of  claim 2 , wherein the second MRM transition is selected from the group consisting of 316.9>263.9 (captan), 316.9>235.9 (captan), 318.9>265.9 (captan), and 318.9>237.9 (captan). 
     
     
         9 . The method of  claim 2 , wherein the second MRM transition is selected from the group consisting of 407.0>59.1 (chlorfenapyr), 424.0>59.1 (chlorfenapyr), and 426.0>59.1 (chlorfenapyr). 
     
     
         10 . The method of  claim 2 , wherein the second MRM transition is 361.2>213.0 (cinerin-II). 
     
     
         11 . The method of  claim 2 , wherein the second MRM transition is 453.1>193.0 (cyfluthrin). 
     
     
         12 . The method of  claim 2 , wherein the second MRM transition is 435.1>193.1 (cypermethrin). 
     
     
         13 . The method of  claim 2 , wherein the second MRM transition is selected from the group consisting of 161.1>44.0 (daminozide) and 161.1>45.0 (daminozide). 
     
     
         14 . The method of  claim 2 , wherein the second MRM transition is 375.2>213.0 (jasmolin II). 
     
     
         15 . The method of  claim 2 , wherein the second MRM transition is selected from the group consisting of 380.8>127.0 (naled) and 382.8>127.0 (naled). 
     
     
         16 . The method of  claim 2 , wherein the second MRM transition is selected from the group consisting of 344.1>69.0 (propiconazole) and 344.1>161.0 (propiconazole). 
     
     
         17 . The method of  claim 1 , further comprising:
 (c) detecting a second MRM transition in the first ionized sample stream, wherein the second MRM transition is selected from the group consisting of 275.8>35.1 (pentachloronitrobenzene), 273.8>35.1 (pentachloronitrobenzene), and 275.8>201.9 (pentachloronitrobenzene).   
     
     
         18 . The method of  claim 1 , further comprising:
 (c) detecting a second MRM transition in the first ionized sample stream, wherein the second MRM transition is selected from the group consisting of 216.8>35.0 (etridiazole) and 218.8>35.0 (etridiazole).   
     
     
         19 . The method of  claim 1 , further comprising:
 (c) detecting a second MRM transition in the first ionized sample stream, wherein the second MRM transition is selected from the group consisting of 346.9>79.0 (chlorfenapyr) and 348.9>81.0 (chlorfenapyr).   
     
     
         20 . The method of  claim 1 , wherein the APCI source uses a nebulizing gas selected from the group consisting of air, nitrogen, carbon dioxide, and argon.