Analysis of Polycyclic Aromatic Hydrocarbons in Fish with Agilent SampliQ QuEChERS AOAC Kit and HPLC-FLD (Publication # 5990-5441EN)
 
Abstract: An HPLC-Florescence Detection (FLD) method was developed and validated for the determination of sixteen polycyclic aromatic hydrocarbons (PAHs) in fish fillets. The analyzed compounds included naphthalene (Nap), acenaphthylene (Acy), acenaphthene(Ace), fluorene (Flu), phenanthrene (Phe), anthracene (Ant), fluoranthene (Fln), pyrene (Pyr), 1,2-benza[a]anthracene (BaA), chrysene (Chr), benzo[e]pyrene (BeP),benzo[e]acenaphthylene (BeA), benzo[k]fluoranthene (BkF), dibenzo[a,h]anthracene(DahA), benzo[g,h,i]perylene (Bghi)P and indeno[1,2,3-cd]pyrene (InP). The method employs a quick, easy, cheap, effective, rugged and safe (QuEChERS) multiresidue sample preparation procedure adopted from the Association of Analytical Communities (AOAC) Official method 2007.01 for extraction and cleanup. The analytes were separated on an Agilent ZORBAX Eclipse PAH HPLC column (4.6 mm × 50 mm,1.8 μm) by gradient elution with a binary system of acetonitrile - water and subsequent fluorescence detection set at appropriate excitation and emission wavelengths.The analyte recoveries ranged from 83.4% to 101% with relative standard deviations ranging from 0.6 to 1.9% at three different fortification levels. The limits of detection and quantification ranged from 0.04 to 0.84 and 0.1 to 2.80 ng/g, respectively.
Analysis of Polycyclic Aromatic Hydrocarbons in Soil with Agilent SampliQ QuEChERS AOAC Kit and HPLC-FLD (Publication # 5990-5452EN)
 
Abstract: An HPLC-Florescence Detection (FLD) method was developed and validated for the determination of sixteen polycyclic aromatic hydrocarbons (PAHs) in soil. The analyzed PAHs include naphthalene (Nap), acenaphthylene (Acy), acenaphthene (Ace), fluorene (Flu), phenanthrene (Phe), anthracene (Ant), fluoranthene (Fln), pyrene (Pyr), 1,2-benza[a]anthracene (BaA), chrysene (Chr), benzo[e]pyrene (BeP), benzo[e]acenaphthylene (BeA), benzo[k]fluoranthene (BkF), dibenzo[a,h]anthracene (DahA), benzo[g,h,i]perylene (Bghi)P and indeno[1,2,3-cd]pyrene (InP). The method employs a quick, easy, cheap, effective, rugged and safe (QuEChERS) multiresidue sample preparation procedure adopted from the Association of Analytical Communities (AOAC) Official method 2007.01 for extraction and cleanup. The analytes were separated on an Agilent ZORBAX Eclipse PAH column (4.6 mm × 50 mm, 1.8 μm) by gradient elution with a binary system of acetonitrile - water with subsequent fluorescence detection set at appropriate excitation and emission wavelengths. The analyte recoveries ranged from 86.0% to 99.2% with relative standard deviations ranging from 0.6% to 1.9% at three different fortification levels. The limits of detection and quantification ranged from 0.005 to 0.78 and 0.02 to 1.6 ng/g, respectively.
 
GC-μECD Analysis and Confirmation of Contact Laboratory Protocol Pesticides in Olive Oil (Publication # 5990-5553EN)
 
Abstract: An olive oil sample obtained from a local grocery store is analyzed for 20 contract laboratory protocol (CLP) pesticides. A QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) with dispersive solid phase extraction (dSPE) procedure cleaned the sample prior to analysis. A dual μECD and dual capillary GC column approach accomplished simultaneous primary and confirmatory analysis. The primary column, an Agilent J&W DB-35ms 30 m × 0.25 mm × 0.25 μm and a confirmatory column, an Agilent J&W DB-XLB 30 m × 0.25 mm × 0.50 μm effectively resolved all 20 CLP pesticides. An unpurged two-way capillary flow technology splitter divided the flow from a single injection port to the two analytical GC columns. Endosulfan sulfate and endosulfan 1 were present in the olive oil sample.
 
Analysis of Pesticide Residues in Apple by GC/MS using Agilent SampliQ QuEChERS Kits for Pre-Injection Clean-Up (Publication #5990-4468EN)
 
Abstract: The QuEChERS method, which stands for Quick, Easy, Cheap, Effective, Rugged and Safe was developed in 2003 by scientists at the USDA. This method was created to easily clean up and prepare food samples for multi-class, multi-residue pesticide analysis. This application note describes the use of the original, non-buffered QuEChERS method to prepare apple samples for residue analysis by gas chromatography/ mass spectrometry (GC/MS). Fifteen pesticides of different classes were studied. The experiments were done using Agilent QuEChERS extraction kits for 10-g samples and dispersive kits for 1-mL sample volumes. The analysis was done by GC/MS using selective ion monitoring (SIM) mode. The limit of quantitation for all the pesticides studied was 10 ng/g in apple using this method. At 200 ng/g, the recoveries ranged from 89% to 102%, and at 10 ng/g, the recoveries ranged from 72% to103%. The relative standard deviations associated with these recoveries were less than 11% in all cases.
 
Determination of Quinolone Antibiotics in Bovine Liver Using Agilent SampliQ QuEChERS Kits by LC/MS/MS (Publication #5990-5085EN)
 
Abstract: This paper presents an analytical method which allows the determination of 11 quinolone antibiotic residue in bovine liver: pipemidic acid, ofloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin, sarafloxacin, cinoxacin, oxolinic acid, nalidixic acid, and flumequine. The procedure involves a rapid and efficient pretreatment by SampliQ QuEChERS kits. The homogenized liver sample was initially extracted in a buffered aqueous, 5% formic acid acetonitrile system. An extraction and partitioning step was performed after the addition of salts. Cleanup was done using dispersive solid phase extraction (dispersive-SPE). The final extracts allowed determination of all compounds in a single run using LC-ESI-MS-MS operating in positive ion multiple reaction monitoring (MRM) mode. Norfloxacin was selected as the internal standard. The accuracy of the method, expressed as recovery, was between 62 and 113%. The precision, expressed as RSD, was between 2.2 and 13.4%. The established limit of quantification (LOQ) was 5 ng/g and is significantly lower than the respective Maximum Residue Limit (MRL) for quinolones in food producing animals.
 
Determination of Sulfonamide Antibiotics in Bovine Liver Using Agilent SampliQ QuEChERS EN Kits by LC/MS/MS (Publication #5990-5086EN)
 
Abstract: This paper presents an analytical method for the determination of nine sulfonamide antibiotic residues in bovine liver: sulfadizine, sulfathiazole, sulfamerazine, sulfamethizole, sulfamethazine, sulfamethoxypyridazine, sulfachloropyridazine, sulfamethoxazole, and sulfadimethoxin. The procedure involves a rapid and efficient pretreatment with SampliQ QuEChERS kits. The homogenized liver sample was initially extracted in a buffered aqueous/1% acetic acid acetonitrile system with an extraction and partitioning step after the addition of salts. Finally, the sample was cleaned up using dispersive solid-phase extraction (dispersive-SPE). The final extracts were analyzed by the sensitive and selective determination of all compounds in a single run using LCESI-MS-MS operating in positive ion multiple reaction monitoring (MRM) mode. Sulfapyridine was selected as the internal standard. The accuracy of the method, expressed as recovery, was between 53 and 93%. The precision, expressed as RSD, was between 2.1 and 16.8%. The established 5 ng/g limits of quantification (LOQ) were much lower than the respective Maximum Residue Limit (MRL) for sulfonamide in animal food products (20-100 ng/g).
 
Analysis of Pesticide Residues in Apple Using SampliQ QuEChERS European Standard EN Kits by LC/MS/MS DetectionВ (Publication # 5990-3938EN)
 
Abstract: This application note describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation approach described in the European Committee Standard (EN) for extraction and cleanup of 16 multiple class pesticide residues of interest in apple. The method employed involves initial extraction in an aqueous/acetonitrile system, an extraction/partitioning step after the addition of salt, and then a cleanup step utilizing dispersive solid phase extraction (dispersive SPE). The two different dispersive SPE clean-up approaches (1 mL and 6 mL sample volume) are evaluated simultaneously after sample extraction. The target pesticides in the apple extracts are then determined by liquid chromatography coupled to an electrospray ionization tandem mass spectrometer (LC-ESI-MS/MS) operating in positive ion multiple reaction monitoring (MRM) mode. The method is validated in terms of recovery and reproducibility. The 5 ng/g of limits of quantitation (LOQ) for pesticides in apple established in this application is well below their regulatory maximum residue limits (MRLs). The spiking levels for the recovery experiments are 10, 50, and 200 ng/g. Excluding pymetrozine, recoveries of the pesticides ranged between 73 and 111% (87% on average), and RSDs below 20% (5.8% on average).
 
Analysis of Pesticide Residues in Apples Using Agilent SampliQ QuEChERS AOAC Kit by LC/MS/MS Detection (Publication # 5990-3937EN)
 
Abstract: This application note describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation approach described in the European Committee Standard (EN) for extraction and cleanup of 16 multiple class pesticide residues of interest in apple. The method employed involves initial extraction in an aqueous/acetonitrile system, an extraction/partitioning step after the addition of salt, and then a cleanup step utilizing dispersive solid phase extraction (dispersive SPE). The two different dispersive SPE clean-up approaches (1 mL and 6 mL sample volume) are evaluated simultaneously after sample extraction. The target pesticides in the apple extracts are then determined by liquid chromatography coupled to an electrospray ionization tandem mass spectrometer (LC-ESI-MS/MS) operating in positive ion multiple reaction monitoring (MRM) mode. The method is validated in terms of recovery and reproducibility. The 5 ng/g of limits of quantitation (LOQ) for pesticides in apple established in this application is well below their regulatory maximum residue limits (MRLs). The spiking levels for the recovery experiments are 10, 50, and 200 ng/g. Excluding pymetrozine, recoveries of the pesticides ranged between 73 and 111% (87% on average), and RSDs below 20% (5.8% on average).
 
Analysis of Pesticide Residues in Apple Using Agilent SampliQ QuEChERS AOAC Kits by GC/MS (Publication # 5990-4068EN)
 
Abstract: This application note describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS), Association of Analytical Communities (AOAC) Official Method 2007.01; sample preparation approach for extraction and cleanup of 16 pesticide residues in apple. The 16 pesticides chosen represent various classes of interest. The method employed involves initial extraction in a buffered aqueous/acetonitrile system, an extraction/partitioning step after the addition of salt, and then a cleanup step utilizing dispersive solid phase extraction (dispersive SPE). The two different dispersive SPE clean-up approaches (1 mL and 8 mL) were evaluated simultaneously after sample extraction. The target pesticides in the apple extracts were then determined by liquid chromatography coupled to an electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) operating in positive ion multiple reaction monitoring (MRM) mode. The method was validated in terms of recovery and reproducibility. The 5 ng/g limit of quantitation (LOQ) for pesticides in apple shown in this application was well below the maximum residue limits (MRLs). The spiking levels for the recovery experiments were 10, 50, and 200 ng/g. Mean recoveries ranged between 76 and 117% (95.4% on average), with RSD below 15% (4.3% on average).
 
Analysis of Pesticide Residues in Apple Using Agilent SampliQ QuEChERS EN Kits by GC/MS (Publication # 5990-4073EN)
 
Abstract: This application note describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) AOAC sample preparation approach for extraction and cleanup of 17 GC-amenable pesticide residues from multiple classes, in apple. The method employed involves initial extraction in a buffered aqueous/acetonitrile system, an extraction/ partitioning step after the addition of salt, and a cleanup step utilizing dispersive solid phase extraction (dispersive SPE). The two different dispersive SPE clean-up approaches used either a 1 mL or 8 mL sample volume and were evaluated in parallel after sample extraction. The target pesticides in the apple extracts were then analyzed by gas chromatography/mass spectrometry (GC/MS) operating in selective ion monitoring (SIM) mode. The method was validated in terms of recovery and reproducibility. The limit of quantitation (LOQ) for most pesticides is 10 ng/g; however, the pesticide Folpet has an LOQ of 50 ng/g in apple. This application employing SampliQ QuEChERS kits produced results well below the maximum residue limits (MRLs) for all the pesticides screened. The spiked levels for the recovery experiments were 10, 50, and 200 ng/g. Recoveries ranged between 70 and 136% (92.5% on average), with RSD below 15% (5.0% on average).
 
Optimizing Recoveries of Planar Pesticides in Spinach using Toluene and Agilent SampliQ AOAC QuEChERS Kits with Graphitized Carbon (Publication #5990-4247EN)
 
Analysis of Pesticide Residues in Spinach Using Agilent SampliQ QuEChERS AOAC Kit by LC/MS/MS Detection (Publication #5990-4248EN)
 
Abstract: This application note describes the impact of toluene addition in the dispersive solid phase extraction (SPE) step on the analysis of pesticides in spinach using Agilent SampliQ QuEChERS AOAC kits for highly pigmented fruits and vegetables. Graphitized carbon black (GCB) is required in the dispersive SPE kits in order to remove high levels of pigments from the matrix. However, it also retains pesticides with planar structures resulting in poor recovery and precision. The eight problematic pesticides found in the original AOAC method, by either LC/MS/MS or GC/MS, generated poor results with about 20% to 60% recovery with >15% relative standard deviation (RSD). In the modified AOAC method, an aliquot of toluene was added to the dispersive SPE cleanup tube, in a ratio of 8:3 (acetonitrile (ACN) extracts/toluene). It significantly improved the extraction efficiency of the problematic planar pesticides. With the modified AOAC method, the eight problematic pesticides generated substantially improved recoveries, 50% to 100%, and < 10% RSD. However, the addition of toluene also introduced more matrix impurities into the final sample, and caused problems for some pesticides which gave good results originally. Therefore, the modified AOAC method cannot be considered a "drop in" replacement for the original AOAC method; but it can be a very useful alternative for the problematic pesticides affected by GCB in the pesticides analysis of highly pigmented matrix.
 
Analysis of Pesticide Residues in Spinach Using Agilent SampliQ QuEChERS AOAC Kits by GC/MS (publication # 5990-4305EN)
 
Abstract: This application note describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) AOAC sample preparation approach for the extraction and cleanup of 13 pesticide residues representing various pesticide classes in spinach. The original AOAC method employed involves initial extraction in a buffered aqueous/acetonitrile system, an extraction/partitioning step after the addition of salt, and a cleanup step using dispersive solid-phase extraction (dispersive SPE). In order to address the significant loss of planar pesticides caused by graphitized carbon black (GCB) in dispersive SPE, a modified method with the addition of toluene was employed. The presence of the target pesticides in the spinach extracts were then determined by liquid chromatography coupled to an electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) operating in positive ion multiple reaction monitoring (MRM) mode. With the combination of original and modified dispersive SPE, the method was validated in terms of recovery and reproducibility for all of the analytes of interest. The 5 ng/g limit of quantitation (LOQ) for pesticides in spinach shown in this application was well below the maximum residue limits (MRLs). The spiking levels for the recovery experiments were 10, 50, and 200 ng/g. Mean recoveries ranged between 64% and 108% (average of 91.9%), with RSD below 10% (average of 3.3%).
 
Analysis of Pesticide Residues in Spinach Using Agilent SampliQ QuEChERS EN Kit by LC/MS/MS Detection (Publication # 5990-4395EN)
 
Abstract: This application note describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) AOAC sample preparation approach for extraction and cleanup of 18 GC-amenable multiple pesticide class residues in spinach. The method employed involves initial extraction in a buffered aqueous/acetonitrile system, an extraction/ partitioning step after the addition of salt, and a cleanup step using dispersive solid phase extraction (dispersive SPE). In order to address the significant loss of planar pesticides caused by graphitized carbon black (GCB) in dispersive SPE, a modified method with addition of toluene was employed for the planar pesticides. The target pesticides in the spinach extracts were then analyzed by gas chromatography/mass spectrometry (GC/MS) operating in selective ion monitoring (SIM) mode. The method was validated in terms of recovery and reproducibility. The limit of quantitation (LOQ) for most pesticides is 10 ng/g; however folpet has an LOQ of 50 ng/g in spinach. This application, employing SampliQ QuEChERS kits, produced results well below the maximum residue limits (MRLs) for all pesticides screened. The spiked levels for the recovery experiments were 10, 50, and 200 ng/g.
 
Determination of Acrylamide in Cooking Oil by Agilent SampliQ QuEChERS AOAC Kit and HPLC-DAD (Publication #5990-5988EN)
 
Abstract: This application note describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) EN sample preparation approach for extraction and cleanup of 13-pesticide residues representing various classes in spinach. Because spinach is considered a highly pigmented matrix, the EN dispersive SPE kit for highly pigmented fruits and vegetables is selected. Graphitized carbon black (GCB) in the amount of 7.5 mg/mL of ACN extract is added to the kit. The target pesticides in the spinach extracts are then determined by liquid chromatography coupled to an electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) operating in positive ion multiple reaction monitoring (MRM) mode. GCB is reported to have a significantly negative impact on the extraction of pesticides with planar structure. However, with the small amount of GCB addition in the EN dispersive SPE kit, our results show that the impact of GCB on planar pesticides is negligible and acceptable quantitation results are obtained. The 5 ng/g limit of quantitation (LOQ) for pesticides in spinach shown in this application is well below the maximum residue limits (MRLs). The spiking levels for the recovery experiments are 10, 50, and 200 ng/g. Mean recoveries range between 60 and 99% (85.4% on average), with an RSD below 11% (5.5% on average).
 
 
 
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