Determination and Confirmation of Identities of Flumequine and Nalidixic, Oxolinic, and Piromidic Acids in Salmon and Shrimp

1996 ◽  
Vol 79 (5) ◽  
pp. 1227-1235 ◽  
Author(s):  
Allen P Pfenning ◽  
Robert K Munns ◽  
Sherri B Turnipseed ◽  
José E Roybal ◽  
David C Holland ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Acetone Extract ◽  
Gas Chromatography Mass Spectrometry ◽  
Optimum Conditions ◽  
Relative Standard ◽  
Diagnostic Ions ◽  
Liquid Chromatographic ◽  
Uv And Fluorescence Detection ◽  
Shrimp Tissue

Abstract A previously published liquid chromatographic (LC) method for determining residues of flumequine (FLU) and nalidixic (NAL), oxolinic (OXO), and piromidic (PIR) acids in catfish tissue was applied to salmon and shrimp muscle. Identities of all 4 residues in salmon and shrimp were confirmed by gas chromatography/mass spectrometry (GC/MS). The tissue is homogenized with acetone, the acetone extract is defatted with hexane, and the quinolones are extracted into chloroform. The extract is further purified by first partitioning into base and then back-extracting from a solution acidified to pH 6.0. Analytes are determined by LC with simultaneous UV and fluorescence detection. Muscle tissue was fortified with each quinolone at 5,10,20,40, and 80 ng/g. Average recoveries and relative standard deviations (RSOs) for salmon, which represent an average of the 5 levels for each analyte, ranged from 75.9 to 90.8% and from 2.25 to 6.40%, respectively. Average recoveries and RSDs for shrimp ranged from 81.3 to 91.2% and from 7.34 to 10.7%, respectively. Identities of OXO, FLU, NAL, and PIR were confirmed in extracts of salmon and shrimp tissue fortified at 10 ng/g by determination of decarboxylated quinolones by GC/MS. Four diagnostic ions were monitored for OXO, FLU, and PIR, and 5 ions were monitored for NAL. All ion relative abundances were within 10% of those calculated for standard decarboxylated quinolones. Optimum conditions for decarboxylation and GC/MS confirmation are given.

Determination of Residues of Flumequine and Nalidixic, Oxolinic, and Piromidic Acids in Catfish by Liquid Chromatography with Fluorescence and UV Detection

1995 ◽  
Vol 78 (2) ◽  
pp. 343-352 ◽  
Author(s):  
Robert K Munns ◽  
Sherri B Turnipseed ◽  
Allen P Pfenning ◽  
José E Roybal ◽  
David C Holland ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Mobile Phase ◽  
Major Ions ◽  
Acetone Extract ◽  
Gas Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method is described for determining residues of flumequine (FLU) and nalidixic (NAL), oxolinic (OXO), and piromidic (PIR) acids in catfish muscle. The identities of 3 of these residues are confirmed by gas chromatography–mass spectrometry (GC–MS). The extraction and cleanup procedures are the same for both determination and identification. Analyte isolation involves homogenizing the tissue with acetone, defatting the acetone extract with hexane, and extracting the compounds into chloroform. The extract is further purified by first partitioning into base and subsequently back-extracting into chloroform after acidifying the aqueous phase. After the solvent is evaporated, the residue is dissolved in mobile phase, and the analytes are determined by LC with fluorescence detection, excitation at 325 nm and emission at 365 nm. Catfish muscle was fortified with each quinolone at 5,10,20,40, and 80 ng/g. Overall average recoveries were 83–94%, with relative standard deviations (RSDs) of 5–7%. The method was evaluated also by a second analyst, who determined 4 quinolones added in combination. Average recoveries of quinolones from catfish fortified at 5,10, and 20 ng/g were 78–90%, with RSDs of 3–6%. The presence in catfish muscle of incurred OXO, FLU, and NAL at the 10 ng/g level was confirmed by analyzing the decarboxylated quinolones by GC–MS. The relative abundances of all 5 major ions for OXO, FLU, and NAL were within 10% of those observed in spectra of standard compounds decarboxylated by the same method.

scholarly journals Liquid Chromatographic Determination of Ampicillin Residues in Porcine Muscle Tissue by a Multipenicillin Analytical Method: European Collaborative Study

2002 ◽  
Vol 85 (4) ◽  
pp. 889-900 ◽  
Author(s):  
Eric Verdon ◽  
Pierric Couëdor ◽  
Pierre Maris ◽  
Michel Laurentie ◽  
P Batjoens ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Muscle Tissue ◽  
Phosphate Buffer ◽  
Collaborative Study ◽  
Porcine Muscle ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A collaborative study involving 14 laboratories was conducted to determine residues of ampicillin in porcine muscle tissue by using a liquid chromatographic method developed for multipenicillin analysis that can quantitate 8 penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, amoxicillin, nafcillin, oxacillin, cloxacillin, and dicloxacillin) at trace levels in muscle tissue. This method involves extraction of the penicillins with phosphate buffer, pH 9, followed cleanup and concentration on a C18 solid-phase extraction column and reaction with benzoic anhydride at 50°C and with 1,2,4-triazole and mercury(II) chloride solution, pH 9.0, at 65°C. The derivatized compounds are eluted isocratically on a C8 column with a mobile phase of acetonitrile and phosphate buffer (pH 6; 0.1M) containing sodium thiosulfate and the ion-pair reagent tetrabutylammonium hydrogen sulfate. The penicillins are detected by UV absorption at 325 nm. The limit of detection and the limit of determination (quantitation) of the method were calculated to be approximately 3–5 and 25 μg/kg, respectively, in accordance with the criteria of European Union (EU) Decision No. 93/256/EEC. In this first interlaboratory study, collaborators were instructed to monitor 4 different penicillin compounds (benzylpenicillin, phenoxymethylpenicillin, ampicillin, and amoxicillin) by analyzing 8 blind samples of muscle tissue in triplicate. These samples were prepared from 2 materials containing different concentrations of incurred ampicillin (63.5 μg/kg for material No. 1 and 358.1 μg/kg for material No. 2) and 1 blank material. The repeatability relative standard deviation and the reproducibility relative standard deviation were 10.2 and 17.4%, respectively, for material No. 1 and 7.0 and 16.0%, respectively, for material No. 2. These results demonstrate that the method is suitable for the determination of ampicillin residues in muscle tissue at the EU maximum residue limit (50 μg/kg) and above. However, the identification of positives by this procedure may need additional confirmation by techniques with greater specificity, such as liquid chromatography combined with mass spectrometry, or tandem mass spectrometry. Investigations regarding the basis of interlaboratory testing studies will further demonstrate the suitability of multiresidue methodology for detecting and quantitating other compounds in the family of penicillin antibiotics.

scholarly journals Multiresidue Determination of Fluoroquinolones in Shrimp by Liquid Chromatography-Fluorescence-Mass Spectrometryn

2005 ◽  
Vol 88 (4) ◽  
pp. 1160-1166 ◽  
Author(s):  
Marilyn J Schneider ◽  
Luz Vazquez-Moreno ◽  
Maria del Carmen Bermudez-Almada ◽  
Ramon Barraza Guardado ◽  
Magdalena Ortega-Nieblas
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Standard Deviation ◽  
Phosphate Buffer ◽  
Fluorescence Detector ◽  
Relative Standard ◽  
Product Ions ◽  
Multiresidue Determination ◽  
Shrimp Tissue

Abstract An efficient multiresidue method for analysis of fluoroquinolones in shrimp has been developed in which quantitation by fluorescence and confirmation by Multiple Stage Mass Spectrometry (MSn) is achieved simultaneously. In this method, shrimp tissue is extracted with ammoniacal acetonitrile and the extract is defatted and then evaporated. After dissolution in basic phosphate buffer, fluoroquinolones in the extract are separated by liquid chromatography and quantitated, taking advantage of their intense fluorescence. Eluate from the fluorescence detector enters the MSn, which allows for confirmation by monitoring ratios of 2 prominent product ions in the MS3 or MS2 spectrum. Using this method, 8 fluoroquinolones have been analyzed in shrimp samples fortified at 10, 25, 50, or 100 ppb levels. Recoveries for desethyleneciprofloxacin, norfloxacin, ciprofloxacin, danofloxacin, enrofloxacin, orbifloxacin, sarafloxacin, and difloxacin ranged from 75 to 92%, with relative standard deviation values of <6%. The limits of quantitation ranged from 0.1 to 1 ng/g. Enrofloxacin and ciprofloxacin were also successfully determined in enrofloxacin-incurred shrimp using this method.

scholarly journals Determination of Se4+ in Drinkable Water by Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry

2000 ◽  
Vol 83 (5) ◽  
pp. 1082-1086 ◽  
Author(s):  
Maurizio Guidotti
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Tap Water ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Drinkable Water

Abstract A method was developed for the selective determination of Se4+ in drinkable water by solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS). Se4+ was selectively derivatized to ethane, 1,1′-selenobis by reaction with sodium tetraethylborate, extracted by the SPME fiber, and determined by GC/MS. Both headspace (HS)–SPME and direct SPME were studied. The method requires only a few milliliters of sample and 20 min for completion. At 2.0 μg/L concentration, the relative standard deviation was 10.1% for HS–SPME and 9.1% for direct SPME. For HS–SPME, the theoretical detection limit was 81 ng/L and 166 ng/L for direct SPME. The recovery rate was 95%. The method was used to determine Se4+ in 10 tap water samples.

scholarly journals Determination of Hexabromocyclododecane in Expanded Polystyrene and Extruded Polystyrene Foam by Gas Chromatography-Mass Spectrometry

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7143
Author(s):  
Tianao Mao ◽  
Haoyang Wang ◽  
Zheng Peng ◽  
Taotao Ni ◽  
Tianqi Jia ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solid Phase ◽  
Expanded Polystyrene ◽  
Gas Chromatography Mass Spectrometry ◽  
Polystyrene Foam ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Extruded Polystyrene Foam

A gas chromatography-mass spectrometry (GC/MS) method for the determination of hexabromocyclododecane (HBCD) in expanded polystyrene and extruded polystyrene foam (EPS/XPS) was developed. The EPS/XPS samples were ultrasonically extracted with acetone and the extracts were purified by filtration through a microporous membrane (0.22 μm) and solid-phase extraction. The samples were analyzed using a GC/MS using the selected ion monitoring mode. The ions 157, 319 and 401 were selected as the qualitative ions, while ion 239 was chosen as the quantitative ion. An HBCD standard working solution with a concentration range of 1.0–50.0 mg/L showed good linearity. The detection limit of HBCD was 0.5 mg/kg, meeting the LPC limit (<100 or 1000 mg/kg). Six laboratories were selected to verify the accuracy of the method, and 10 samples were tested. The interlaboratory relative standard deviation range was 3.68–9.80%. This method could play an important role in controlling HBCD contamination in EPS/XPS.

Determination of Flunixin in Milk by Liquid Chromatography with Confirmation by Gas Chromatography/Mass Spectrometry and Selected Ion Monitoring

1995 ◽  
Vol 78 (4) ◽  
pp. 959-966 ◽  
Author(s):  
Heidi S Rupp ◽  
David C Holland ◽  
Robert K Munns ◽  
Sherri B Turnipseed ◽  
Austin R Long
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Enzyme Treatment ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Flunixin Meglumine ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract A liquid chromatographic (LC) method was developed for the determination of flunixin (FNX) in raw bovine milk. The milk was acidified and mixed with silica gel, and the mixture was packed into a chromatographic column. The column was defatted with water-saturated dichloromethane–hexane (30 + 70, v/v), and the analyte was eluted with EtOAc. The EtOAc extract was washed with water at pH 3.5, the water was discarded, and the EtOAc layer was then extracted with 0.1 M NaOH. The aqueous layer was drained, passed through a primed C18 solid-phase extraction (SPE) column, and eluted with EtOAc. The EtOAc layer was dried under N2, taken up in a solution of MeOH–(5 mM tetrabutylammonium [TBA]–H2PO4 + 2 mM NaOH) (50 + 50), sonicated, and filtered. FNX was determined by LC using a C18 column (ODS Hypersil), a mobile phase mixture of 58% A (MeOH) and 42% B (5 mM TBA–H2PO4 + 2 mM NaOH), and a diode-array ultraviolet detector at 285 nm. FNX was determined in raw milk at 5 spiking levels (5,10,20,40, and 80 ng drug/mL milk). Absolute recoveries ranged from 69.6 to 74.4%, and relative standard deviations ranged from 1.1 to 6.9%. The limit of quantitation was 1.7 ng drug/mL milk. A lactating cow was dosed intravenously (2.2 mg/kg) with flunixin meglumine (Banamine) to generate incurred milk residues. FNX residues ranged from 7.34 ng/mL at 16 h postdose to 1.74 ng/mL at 24 h postdose. Both levels were obtained with additional β-glucuronidase treatment (almost no incurred drug was detected at these low levels without the enzyme treatment). The presence of FNX in incurred milk was confirmed by gas chromatography/mass spectrometry with selected ion monitoring.

Gas-Liquid Chromatographic Headspace Method for Vinyl Chloride in Vinegars and Alcoholic Beverages

1976 ◽  
Vol 59 (1) ◽  
pp. 30-31
Author(s):  
David T Williams
Keyword(s):  
Mass Spectrometry ◽  
Vinyl Chloride ◽  
Limit Of Detection ◽  
Direct Injection ◽  
Headspace Analysis ◽  
Alcoholic Beverages ◽  
Gas Chromatography Mass Spectrometry ◽  
Injection Methods ◽  
Liquid Chromatographic

Abstract Vinyl chloride (VC) is determined in vinegars and alcoholic beverages by gas-liquid chromatographic headspace analysis. The lower limit of detection is 10 ppb and confirmation by gas chromatography-mass spectrometry, single ion monitoring at m/e 62, is possible at this level. Comparison of the headspace and the direct injection methods for the determination of VC in vinegars and alcoholic beverages showed that the results obtained by the 2 methods were not significantly different (P&gt;0.05).

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