scholarly journals Optimization and Automation of AOAC Official Method 971.47 for Determination of Roxarsone in Feed

1996 ◽  
Vol 79 (4) ◽  
pp. 1012-1017 ◽  
Author(s):  
Gregory K Webster ◽  
Rostyk Mandzu ◽  
Lisa A Drong ◽  
William H Williams ◽  
Brian G Mess ◽  
...  

Abstract AOAC Official Method 971.47 was optimized for use with solid-phase extraction (SPE) using the same activated carbon referenced in the original method. The optimization of AOAC 971.47 begins after the roxarsone is extracted into the 2% K2HPO4 solution of the original method; instead of 30 mL, 9 mL is pipetted into a test tube. Next, to flocculate the protein, 300 μL HCI is pipetted into the tube and mixed. After 15 min, the contents of the tube are filtered through a 0.45 μm nylon membrane filter equipped with a glass prefilter. Next, 7 mL clear filtrate is pipetted into a new test tube, followed by the addition of 234 μL NaOH, and the contents of the tube are mixed. The filtrate is then passed through a 400 mg bed of activated carbon packed in a 3 mL SPE tube at a flow rate of 1 mL/min. The spectrophotometric analysis of the eluate is not changed from the original AOAC 971.47. The optimized method was validated and semiautomated. Results of roxarsone determination by the optimized procedure were found to be acceptable at all levels of approved claims. For the commercial feed samples analyzed, recoveries by the automated method ranged from 93.7 to 104% of the results reported by an independent laboratory using AOAC 971.47.

2015 ◽  
Vol 98 (3) ◽  
pp. 622-627 ◽  
Author(s):  
Kristin Bjornsdottir-Butler ◽  
F. Aladar Bencsath ◽  
Ronald A. Benner, Jr

Histamine is the main causative agent in scombrotoxin fish poisoning, the most frequently reported illness related to fish consumption. The AOAC official method for histamine determination in fish is the fluorometric method AOAC 977.13, which is sensitive and reproducible but somewhat labor intensive and time consuming. We investigated multiple modifications to this method in an attempt to reduce assay time and increase sample throughput while maintaining the performance of the original method. Some of the attempted modifications negatively affected the performance characteristics of the method. However, omitting the heating step during extraction and replacing the cuvette style fluorometer with a microplate reader retained method performance while increasing sample throughput. Therefore, we adopted these modifications and conducted a single-laboratory validation. The recovery, precision (RSD), and LOD of the modified method assessed by the single-laboratory validation ranged from 92 to 105%, 1 to 3%, and 0.2 to 0.5 ppm, respectively, in tuna, mahi-mahi, and Spanish mackerel samples. We conclude that the AOAC 977.13 fluorometric method, modified as described, will improve assay time and sample throughput efficiency cumulatively, as the number of sample units analyzed increases. We anticipate that this modified method could be used by regulatory agencies and other laboratories following successful multilaboratory validation.


1970 ◽  
Vol 53 (1) ◽  
pp. 3-6
Author(s):  
R. Bruce Klemm ◽  
Mary E. Ambrose Klemm

Abstract The AOAC official method, 24.029–24.035, for the determination of fluorine in foods was modified slightly to o btain quantitative recoveries of fluorine from samples of fish protein concentrate (FPC). The most important alterations include the use of steam distillation, the addition of finely ground silica sand in the distillation, a decrease in the distillation temperature, and the utilization of direct titration. Recoveries of fluoride added to FPC before ashing, using this modified method, averaged 96.0 ± 3.0%. Our results are in agreement with those of several other analysts who used a variety of methods.


2014 ◽  
Vol 19 (1) ◽  
pp. 27
Author(s):  
Haryoto Kusnoputranto ◽  
Setyo S Moersidik ◽  
Djarot S Wisnubroto ◽  
Murdahayu Makmur

Ledakan mikroalga sering dilaporkan terjadi di Teluk Jakarta, dimana di lokasi tersebut juga terdapat kegiatan budidaya kerang hijau (Perna viridis). Terkait dengan hal tersebut maka dilakukan studi akumulasi dan depurasi toksin PSP (Paralytic Shellfish Poisoning) pada kerang hijau. Studi akumulasi dilakukan di bagan kerang hijau perairan Cilincing Jakarta Utara, dengan memisahkan kerang hijau yang berukuran sama dan ditempatkan kembali ke bagan. Sampling dilakukan setiap minggu selama 2 bulan dan diukur juga kelimpahan fitoplankton, pH, suhu dan salinitas perairan. Depurasi dilakukan di Unit Depurasi Kekerangan KKP Panimbang Banten, yang dilakukan selama 24 jam. Pencuplikan  sampel dilakukan setiap jam pada 4 jam pertama dan setiap 2 dan 3 jam pada waktu berikutnya. Penentuan konsentrasi toksin PSP dilakukan dengan menggunakan HPLC detektor fluoresensi. Prosedur preparasi, ekstraksi dan pengukuran konsentrasi toksin mengikuti Manual AOAC Official Method 2005.06 untuk toksin PSP dalam kekerangan. Akumulasi toksin PSP oleh kerang hijau di perairan Cilincing pada bulan Januari–Pebruari 2011 berkisar antara 4,11–11,96 µg STX eq. per 100 g dan tidak mempunyai korelasi dengan kelimpahan Dinoflagelata di perairan. Hal ini disebabkan uji akumulasi tidak dilakukan pada saat blooming mikroalga. Uji depurasi selama 24 jam mengeliminasi toksin PSP sebesar 60%, sehingga bisa diajukan sebagai sistem pemutus rantai toksin dari mikroalga ke manusia. Kata kunci: akumulasi, depurasi, PSP toksin, kerang hijau, Cilincing Microalgae blooms have been frequently reported in the Jakarta Bay, which is also the location of green mussel (Perna viridis) aquaculture. Accumulation and depuration of Paralytic Shellfish Poisoning (PSP) toxin in the green mussels were investigated in the field, where the toxin accumulation studies conducted in the mussel farming at Cilincing, North Jakarta. Accumulation test carried out by placing back the selected green mussel (equal size) into the mussel farming. Every week for 2 months, the green mussel were collected from mussel farming and transported to the laboratory. The fitoplankton abundance also was checked including pH, Suhue and salinitiy paramaters. Toxin depuration was conducted at Clams Sanitation Unit at Panimbang Banten. The depuration studies were conducted for 24 hours with sampling every hour in the first 4 hours and every 3 and 2 hours until the 24th hour. Preparation, extraction and toxin concentration measurements performed by following the Manual AOAC Official Method 2005.06 for PSP toxin in oyster. This research concluded that the accumulation of PSP toxin by green mussel, Perna viridis in the mussel farming at Cilincing, North Jakarta in ranged between 4,11–11,96 µg STX eq. per 100 g during January–February 2011. No correlation between PSP toxin concentration in the green mussel, Perna viridis with abundance of the PSP toxin sources phytoplankton, because the study wasnt done when microalgae blooming. The depuration processes was eliminate 60% the PSP toxins for 24 hours depuration processing. It can be proposes as a banded system the PSP toxin from algae to human being. Keywords: accumulation, depuration, PSP toxin, green mussel, Cilincing


1970 ◽  
Vol 53 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Donald L Andersen

Abstract A new GLC method for the determination of allyl isothiocyanate in mustard seed was compared to a method of the Midwest Research Institute and to a combination of the AOAC official method and the proposed method. Twelve collaborators compared the AOAC method and the GLC method, using whole mustard seeds. Each collaborator assayed three seed portions by both methods. The range, standard deviation, and coefficient of variation are less for each seed portion by the proposed than by the official method. The average recovery value of allyl isothiocyanate in the prepared standard solutions is lower, using the proposed GLC procedure, but seed assay values are significantly and consistently higher for each seed portion when compared with the results for the AOAC method. Reports from the collaborators also indicate that the proposed method is rugged, as the GLC column preparation was subjected to many changes. It is recommended that the GLC method be adopted as official first action.


1997 ◽  
Vol 80 (6) ◽  
pp. 1235-1271 ◽  
Author(s):  
Jane E Fox Dobson ◽  
Foster D McClure ◽  
Alvin P Rainosek ◽  
K Dashiell ◽  
J Fox Dobson ◽  
...  

Abstract An intralaboratory1collaborative study evaluated a modified version of AOAC Official Method 971.13 for determining the fish flesh content (FFC) in frozen coated fish products by comparing it with the on-line method. Eleven collaborators analyzed 36 products (a total of 6336 test samples). Each product targeted one of 4 percent fish flesh (PFF) levels (35,50,65, and 80). Products were manufactured from one of 3 raw materials (fillet blocks, minced blocks, and natural fillets) and processed in one of 4 forms (sticks, portions, formed portions, and fillets) and one of 4 styles (raw breaded, batter-dipped, precooked, and fully cooked). Each “official” test sample was tracked through the processing system and weighed (1) before battering and/or breading and, depending on product style, before frying; and (2) after battering and/or breading and, depending on product style, after frying; so that it served as its own control.


1996 ◽  
Vol 79 (4) ◽  
pp. 907-916 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming

Abstract A modified Mojonnier ether extraction method for determination of the fat content of cream was developed based on the method for milk (AOAC Official Method 989.05). The cream Babcock method (AOAC Official Method 920.111 B-C) was modified to harmonize with the milk Babcock method (AOAC Official Method 989.04) and to clarify procedural details. Using the AOAC collaborative study format, 10 laboratories tested 9 pairs of blind duplicate heat-treated cream samples with a fat range of 30-45% using both methods. The statistical performance (invalid and outlier data removed) was as follows: mean % fat = 37.932, sr = 0.125, sR = 0.151, RSDr = 0.330, RSDR = 0.398, r = 0.354, and R = 0.427 for the ether extraction method. For the Babcock method, mean % fat = 38.209, sr = 0.209, SR = 0.272, RSDr = 0.548, RSDR = 0.712, r = 0.592, and R = 0.769. Average test results for fat from the Babcock method were 0.277% (absolute fat) greater than for the Mojonnier ether extraction method. The difference between methods, as a percentage of the average fat content of the samples, was 0.73%. This agrees with differences observed between the 2 methods for milk when 10 to 17 laboratories tested 7 milk samples in blind duplicate at bimonthly intervals over a 4-year period (average difference 0.029% fat, 0.78% as a percentage of average fat content). The Mojonnier ether extraction and Babcock methods for fat in cream have been adopted by AOAC INTERNATIONAL. The new Babcock method replaced the AOAC Official Method 920.111 B-C.


2008 ◽  
Vol 91 (2) ◽  
pp. 365-369 ◽  
Author(s):  
Philip T Feldsine ◽  
David E Kerr ◽  
George S Shen ◽  
Andrew H Lienau

Abstract The Visual Immunoprecipitate (VIP®) for the Detection of Listeria in Foods and Environmental Surfaces, AOAC Official Method 997.03, has been modified to use a simplified housing for the device. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture methods. Two food matrixes and one environmental surface were analyzed. In total, valid results were obtained from 145 samples and controls. Results showed that the modified VIP for Listeria spp. is equivalent to the reference culture methods for the detection of Listeria.


1999 ◽  
Vol 82 (5) ◽  
pp. 1146-1155 ◽  
Author(s):  
Jonathan W DeVries ◽  
Lori Kjos ◽  
Linda Groff ◽  
Martin Bob ◽  
Cernohous Kristi ◽  
...  

Abstract Quantitation of fat in foods has been performed successfully with AOAC Official Method 996.06. A number of situations have been encountered that render the method note, “Note: For any unknown or uncalibrated peaks, use the nearest calibrated fatty acid response factors and conversion factors,” inaccurate. Identification of extraneous compounds and availability of additional standard fatty acid methyl esters combined with mass spectral data lead to the recommendation of modifications in Official Method 996.06. The stepwise performance of the method remains unchanged.


1998 ◽  
Vol 61 (7) ◽  
pp. 913-916 ◽  
Author(s):  
PHYLLIS ENTIS ◽  
IRINA LERNER

A study was undertaken to compare β-glucuronidase-positive Escherichia coli counts produced by the ISO-GRID hydrophobic grid membrane filter method using SD-39 agar (test method) with those produced by AOAC Official Method 990.11, an existing ISO-GRID method using lactose monensin glucuronate agar and buffered MUG agar (reference method). The methods were evaluated using 21 food products, with three independent lots of five replicate samples analyzed per product by both methods. The test and reference methods were statistically equivalent for 19 of the 21 products; frozen, raw ground lamb produced significantly higher counts using the reference method, whereas counts obtained from cottage cheese were significantly higher using the SD-39 agar-based method.


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