scholarly journals Single-Laboratory Validation of a Method for the Determination of Furan in Foods by Using Static Headspace Sampling and Gas Chromatography/Mass Spectrometry

2006 ◽  
Vol 89 (5) ◽  
pp. 1417-1424 ◽  
Author(s):  
Patricia J Nyman ◽  
Kim M Morehouse ◽  
Timothy P McNeal ◽  
Gracia A Perfetti ◽  
Gregory W Diachenko

Abstract A headspace gas chromatography/mass spectrometry method was developed and validated in-house for the determination of furan in foods. The method of standard additions with d4-furan as the internal standard was used to quantitate furan. The limit of detection and limit of quantitation (LOQ) values ranged from 0.2 and 0.6 ng/g, respectively, in apple juice to 0.9 and 2.9 ng/g, respectively, in peanut butter. Recoveries were obtained at 0.5, 1, 2, and 3 times the LOQ. At 1, 2, and 3 times the LOQ, the recoveries ranged from 89.4 to 108%, and the relative standard deviations ranged from 3.3 to 17.3% for all the matrixes. For apple juice, chicken broth, and infant formula, the averaged coefficients of determination from the linear regression analyses were >0.99 with each food fortified at 0.5, 1, 2, and 3 times the LOQ. The coefficients of determination were >0.99 for green beans and 0.96 for peanut butter with the foods fortified at 1, 2, and 3 times the LOQ. Within-laboratory precision was determined by comparing the amounts of furan found in 18 samples by 2 analysts on different days with different instruments. For most of the foods, the difference between the amounts found by each analyst was <18%. The method was used to conduct a survey of >300 foods. The furan levels found ranged from none detected to 174 ng/g.


1995 ◽  
Vol 78 (4) ◽  
pp. 959-966 ◽  
Author(s):  
Heidi S Rupp ◽  
David C Holland ◽  
Robert K Munns ◽  
Sherri B Turnipseed ◽  
Austin R Long

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.



1989 ◽  
Vol 72 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Lee Q Huang

Abstract A multiresidue method was developed for the simultaneous determination of low parts per billion (ppb) concentrations of the herbicides alachlor, metolachlor, atrazine, and simazine in water and soil using isotope dilution gas chromatography/mass spectrometry (GC/MS). Known amounts of 15N,13C-alachlor and 2H5-atrazine were added to each sample as internal standards. The samples were then prepared by a solid phase extraction with no further cleanup. A high resolution GC/low resolution MS system with data acquisition in selected ion monitoring mode was used to quantitate herbicides in the extract. The limit of detection was 0.05 ppb for water and 0.5 ppb for soil. Accuracy greater than 80% and precision better than 4% was demonstrated with spiked samples.



2009 ◽  
Vol 92 (1) ◽  
pp. 302-306 ◽  
Author(s):  
Xiao-Jing Yan ◽  
Xiao-Mei Liang ◽  
Yan-Jun Xu ◽  
Shu-Hui Jin ◽  
Dao-Quan Wang

Abstract A method was developed for the determination of 7B3 (12-propyloxyimino-1,15-pentadecanlactam), a novel macrolactam fungicide, by liquid chromatography/mass spectrometry (LC/MS) with positive electrospray ionization (ESI+). The method used a reversed-phase C18 column and acetonitrilewater (60 + 40, v/v) mobile phase. The quick, easy, cheap, effective, rugged, and safe method was used for extraction of 7B3 from cotton plants, which involved the extraction of 10 g homogenized sample with 10 mL acetonitrile, followed by the addition of 4 g anhydrous MgSO4 and 1.0 g NaCl. After centrifugation, 1 mL of the buffered acetonitrile extract was transferred into a tube containing 50 mg primary secondary amine sorbent and 100 mg anhydrous MgSO4. After shaking and centrifugation, the final extract was transferred to an autosampler vial for concurrent analysis by LC/MS. The results of 7B3 determined by LC/MS in the selective ion monitoring mode were linear, and the matrix effect of the method was evaluated. The average recoveries of 7B3 fortified at different levels were within 84.1100.2, and the relative standard deviations were <7.5 for all samples analyzed. The method limit of detection and the limit of quantitation values were 0.03 and 0.1 mg/kg, respectively. The proposed method was successfully applied to determine 7B3 residues in practical samples. This method is sensitive, accurate, reliable, simple, and safe.



2000 ◽  
Vol 83 (5) ◽  
pp. 1082-1086 ◽  
Author(s):  
Maurizio Guidotti

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.





Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7143
Author(s):  
Tianao Mao ◽  
Haoyang Wang ◽  
Zheng Peng ◽  
Taotao Ni ◽  
Tianqi Jia ◽  
...  

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.



2020 ◽  
Vol 17 (34) ◽  
pp. 362-372
Author(s):  
Yosi ARISTIAWAN ◽  
Dillani PUTRI RAMADHANINGTYAS ◽  
Isna KOMALASARI ◽  
Dyah STYARINI ◽  
Nuryatini HAMIM

Organochlorine insecticides are still exploited among the most prominent pesticides for plant protection purposes. Known for having hazardous to humans and persistent in the environment properties, it is necessary to build an accurate method for detecting organochlorine insecticides in food and environmental substances. Isotope-dilution gas chromatography-mass spectrometry (ID-GC-MS) is a versatile coupling measurement system and high order method that combines both selectivity, sensitivity and high accuracy. The present paper aims at showing the methodology of the organochlorine insecticides (alpha-HCH and gamma-HCH) determination in ginseng by using ID-GC-MS. The described method covered sample preparation using an organic solvent (hexane) extraction, followed by florisil cleaning-up. After the reconstitution of the solvent base, the measurement was conducted by using ID-GC-MS in the optimal instrument parameter. Using the determined optimal conditions, the parameters such as sensitivity, linearity, precision, and accuracy were studied for validation of the ID-GC–MS method. The limit of detection and the limit of quantitation of the instrument were 0.5 ng/g and 2.0 ng/g for both analytes. The method showed linearity with the correlation coefficient of 0.999 for both alpha-HCH and gamma-HCH over the concentration range of 1‒300 ng/g. The precision ranged from 3.0 to 3.7% and 2.4 to 3.3% for alpha-HCH and gamma-HCH, respectively. The mean recoveries for alpha-HCH and gamma-HCH were found at 98.0 and 95.6%, respectively. Following method validation, the measurement uncertainty of the alpha-HCH and gamma-HCH determination was evaluated according to EURACHEM GUM guide at a 95 % confidence level (k = 2). The expanded uncertainty in the measurement of alpha-HCH and gamma-HCH was 5.4% and 8.2%, respectively. All these parameters demonstrate the high sensitivity of the offered method and the success of the described method in the determination of alpha-HCH and gamma-HCH in ginseng sample.



Author(s):  
Hien Dang Thu ◽  
Ngoc Anh Mai Thi ◽  
Hong Ngoc Nguyen Thi ◽  
◽  
◽  
...  

In this study, a method for determination of six phytosterols by gas chromatography-mass spectrometry with derivatization in vegetable oils was validated. The samples were hydrolyzed in an alkaline media at 70&deg;C for 60 min. Then, the samples were performed liquid-liquid extraction with toluene. The phytosterols are derivatized to trimethylsilyl ethers and then analyzed by gas chromatography-mass spectrometry. The limit of detection and limit of quantification was 5 and 15 mg/kg, respectively. Recoveries of six phytosterols were between 93.5% and 101%.



2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Guo-wei Zhou ◽  
Yong-mei Li ◽  
Chun-ni Liu ◽  
Hong-min Ren ◽  
Hai-ying Li

A simple, fast, and reliable method was established for simultaneous determination of 43 pesticides in Schizonepeta tenuifolia. The samples were prepared using solid-phase extraction (SPE) method. Pesticides were extracted from Schizonepeta tenuifolia using acetonitrile, cleaned with Pesticarb/NH2, and eluted by mixed solvents of acetonitrile and toluene (3 : 1, v/v). Selected pesticides were identified using DB-35MS capillary column and detected by gas chromatography mass spectrometry. Samples were quantified by external standard method. Recoveries for the majority of pesticides at spike levels of 0.2, 0.5, and 1 mg kg−1 ranged between 70 and 120% (except for Chlorothalonil, Thiamethoxam, and Dicofol), and the relative standard deviations (RSDs n = 6) were 1.32%–13.91%. Limits of detection (LODs) were 0.0011–0.0135 mg kg−1, whereas limits of quantification (LOQs) were 0.0038–0.0451 mg kg−1. The satisfactory accuracy and precision, in combination with a good separation and few interferences, have demonstrated the strong potential of this technique for its application in Schizonepeta tenuifolia analysis.



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