Showing papers in "Journal of AOAC International in 1984"

Aflatoxin Levels in Airborne Dust Generated from Contaminated Corn During Harvest and at an Elevator in 1980

Abstract: of the combine, the average aflatoxin level was 2550 ng/g of dust. At one time, the operator was exposed to airborne dust containing 1360 ng/g while inside the combine cab. An airborne dust sample taken with a personal sampler during transfer of the corn to a truck had 52 000 ng/g. Airborne dusts collected while corn containing aflatoxin (1240­ 1850 ng/g) was being ground and fed had total aflatoxin levels ranging from nondetected to 43 700 ng/g. Airborne dust, bulk corn, and settled dust samples were collected at a grain elevator. Airborne dust samples collected during the delivery of corn in farm trucks to the elevator had an average of 1240 ng total aflatoxin/g. The airborne dust samples taken while corn was being unloaded from the elevator into trucks and railroad cars had lower average aflatoxin levels than those in dusts collected during delivery. Settled dusts in the elevator had 173-669 ng total aflatoxin/g. The highest aflatoxin level in the air in the elevator was 13 000 ng/cu. m near the conveyor belt. Airborne dust samples collected by personal samplers on elevator workers contained aflatoxin levels of 429-1300 ng/g; aflatoxin levels in the air were 9-1120 ng/cu.

Malt Beverages and Brewing Materials: Gas Chromatographic Determination of Ethanol in Beer

Abstract: Adoption de cette methode, apres etude interlaboratoires, comme methode de reference pouvant etre automatisee

Verification of authenticity of orange juice

Abstract: En comparant les donnees de la litterature relatives aux differentes techniques et aux differents criteres d'identification de l'adulteration des jus d'orange, on montre que l'analyse isotopique (δ 18 O) permet d'authentifier un echantillon : les seuls jus authentiques presentant un indice positif

Karl Fischer Determination of Water in Oils and Fats: International Collaborative Study

Abstract: Les resultats obtenus permettent de proposer cette methode comme methode officielle. Application a l'huile de soja

Recovery of Salmonella Species from Nonfat Dry Milk Rehydrated Under Rapid and Reduced Pre-enrichment Conditions: Collaborative Study

Abstract: A collaborative study was conducted to compare the relative efficiency of the AOAC rapid rehydration method with the reduced rehydration soak method for the recovery of Salmonella species from nonfat dry milk (NFDM). In the AOAC method, a 25 g sample of NFDM is rapidly rehydrated at a 1:9 sample/water ratio and mixed by swirling. After 60 min, the flask contents are adjusted to a pH of 6.8, and 0.45 mL of 1% aqueous brilliant green dye solution is added. The flasks are then incubated at 35 degrees C. In the soak method, a 25 g sample of NFDM is gently added to the sterile brilliant green (BG) water at a 1:9 sample/BG water ratio and allowed to soak undisturbed for 60 min at room temperature before incubation. Twelve collaborators analyzed 3 shipments of samples with the following results for the AOAC and soak methods: shipment 1-31 and 46 positive samples, respectively, with a 48% increase in detection by the soak method; shipment 3-45 and 66 positive samples, respectively, with a 47% increase in detection by the soak method; shipment 2--no significant difference in recovery of Salmonella species by the 2 methods. It is recommended that the official final action method for the detection of Salmonella species, 46.054-46.067, be revised to use the soak method for the analysis of nonfat dry milk.

Extraction of Pesticides from Environmental Samples by Steam Distillation

Abstract: Extraction de plusieurs pesticides d'echantillons de sol, de tissus vegetaux et d'air. Ce procede necessite de faibles quantites de solvant organique et supprime le nettoyage de l'extrait. Il est apparemment limite aux pesticides assez polaires, stables a la vapeur ou a la chaleur

Liquid Chromatographic Determination of Chlortetracycline in Premixes

Abstract: Description d'une technique de dosage de cet antibiotique et comparaison avec les resultats obtenus par la methode AOAC de chromatographie sur plaque cylindrique

Determination of residual levels and migration of benzene from styrene-containing polymers

Abstract: Dosage, par chromatographie en phase gazeuse, et confirmation, par spectrometrie de masse, du benzene residuel dans une serie de matieres plastiques destinees a la fabrication d'emballages alimentaires. Les essais de migration a differentes temperatures (temperatures de pasteurisation) indiquent que la teneur en benzene peut atteindre 3,47 ppm

Improved Storherr lube for Assisted and Sweep Co-Distillation Cleanup of Pesticides, Poly chlorinated Biphenyls, and Pentachlorophenol from Animal Fats

Abstract: A procedure is presented for the simultaneous extraction from animal fat and quantitation of 15 pesticide residues, 4 polychlorinated biphenyl (PCB) formulations, and pentachlorophenol (PCP) Silanization of the Storherr tube packing reduces thermal decomposition and allows for residue recoveries in excess of 88% from pork, beef, chicken, sheep, and rabbit fat This Storherr tube performs well in either the assisted distillation or sweep co-distillation mode of operation Detection limits of 2-5 ppb for the pesticides and 10 ppb for the PCBs are readily attained

Detection of adulteration in grated cheese by using calcium, phosphorus, magnesium, and lactose indices

Abstract: Les rapports moyens calcium/phosphore et calcium/magnesium se situent respectivement a 1,55 et 23,3 pour les fromages a râper authentiques (Parmesan et Romano). Les fromages de brebis ne presentent pas le meme rapport Ca/Mg que les fromages a base de lait de vache

Conception, birth, and development of three new successful analytical concepts

Abstract: Les 3 techniques considerees sont la spectrometrie d'emission atomique, la spectrometrie de fluorescence atomique et la spectrometrie de masse, toutes 3 utilisant un plasma induit par haute frequence

Modification of Liquid Chromatographic Method for Analysis of Rotenone Formulations

Abstract: Modifications ha,·c been made on the official first action liquid chro• matographic melhod for analysis of rote none formulations, Methanolwater was replaced wilh acetonitrile-waler as the eluant and methanol was substituted for dioxane as the extracting solnnt. The extraction procedure has been changed from 1 1⁄2 h of rotary shaking to S min of sonirntion. The rest of the procedure is identical to the published method. For 9 different products analyzed 6 times each, the percent coeffkienls of Yarialion were all below 2.40. Fi\\'e of these 9 samples were preYiousl)' used in the rotenone collaborative study. A comparison of results from both studies showed that the modifications did not affect the percent rotenone found. It is recommended that these changes be tested in a mini-collaboralive study,

Improved Gas Chromatographic Determination of Sorbitan Fatty Acid Esters in Confectionery Products

Abstract: Description du dosage de monostearate de sorbitan (emulsifiant) par chromatographie gazeuse avec une limite de detection de l'ordre de 0,01 %

Capillary Gas Chromatographic Determination of Pentachlorophenol Residues in Tallow Following Automated Gel Permeation Cleanup

Abstract: Description d'une methode de dosage de ce produit toxique utilise comme pesticide a large spectre d'action et qui contamine les aliments du betail. La limite de detection est de l'ordre de 0,001 ppm, les quantites trouvees dans les echantillons de saindoux varient de 0,005 a 0,05 ppm

Determination of cyanogenic glycoside in seeds by molecular absorption spectrometry in the gas phase

Abstract: Methode de mesure des teneurs en amygdaline et prunasine de graines de pomme, cerise, amande et peche