bluuebunny/crossref_metadata_2025_split huggingface dataset:
Workshop on the Determination of Lead in Foods by Graphite Furnace Atomic Absorption Spectrometry: Preliminary Report
Authors: Dabeka Robert W 
Published: February 2020

Abstract
Seven analysts with various degrees of trace element experience participated in a workshop on the determination of lead in foods containing 1-1000 ng lead/g. Each analyst independently performed 4 projects: contamination control, rapid screening for lead in canned milks, rapid determination of lead in foods, and solvent extraction determination of lead in foods. Accuracy and precision for all methods were good, and, using the solvent extraction method, analysts were able to accurately analyze milk containing 2 ng lead/g with a reproducibility standard deviation of 0.6 ng/g, including individual outliers, and 0.3 ng/g when outliers were rejected. Recovery at the 10 ng/g spiking level for milk averaged 107%. The results were exceptional considering that one of the analysts was a pesticide chemist, 5 other analysts spend only part of their time in trace element analysis, clean-room facilities were not used for any part of the study, the solvent extraction technique was preceded by a HNO3-HCIO4 digestion and was relatively complex, and the labware used for the entire workshop including digestions was either Pyrex or uncleaned, disposable polystyrene test tubes. The results of the workshop demonstrate that accurate, background-level lead determinations can be made inexpensively in normal laboratories, provided analysts are properly instructed in contamination control.
Reverse Phase Liquid Chromatographic Determination of Vitamins D2 and D3 in Milk
Authors: Muniz Juan F , Wehr C Timothy , Wehr H Michael 
Published: February 2020

Abstract
A single column reverse phase high pressure liquid chromatographic method is described for the determination of vitamins D2 and D3 in fluid milk. Resolution of vitamin D2 from D3 is helpful for use as an internal standard. The method involves overnight saponification at room temperature, extraction of unsaponifiables, precipitation of cholesterol, and aluminum oxide column cleanup. Sample extracts were chromatographed under isocratic conditions on a 10 μVydac reverse phase column using acetonitrile- methanol (90 + 10) as the mobile phase. In addition, a MicroPak MCH-5 reverse phase column with acetonitrile as the mobile phase was used with an automatic system for one product type. Thirty samples each of homogenized (3.8% fat), low fat (2.07c fat), and skim (≤0.5% fat) milk spiked with 200,400, and 600 IU vitamin D/qt were analyzed. Coefficient of variation (CV) and percent recovery for each product type and each spike level of vitamins D2 and D3 were calculated from 10 replicate analyses. Vitamin D2 recoveries for all product types at the 3 fortification levels varied from 85.2 to 99.7%; vitamin D3 recoveries varied from 85.9 to 98.8%. The minimum detectable quantity of vitamin D in milk was 15IU/qt.
Use of Post-Column Derivatization in Liquid Chromatographic Determination of Sulfamethazine and Sulfathiazole in Feeds and Feed Premixes
Authors: Stringham Rodger W , Mundell Elizabeth C , Smallidge Robert L 
Published: February 2020

Abstract
Sulfonamide drugs are extracted from feed and feed premixes by shaking with 0.15N HC1 in 25% methanol. The extract is diluted, clarified, and chromatographed on a reverse phase Cis column. Mobile phases used are methanol-2% acetic acid (35 + 65) and acetonitrile-2% acetic acid (18 + 82) for sulfamethazine (SMT) and sulfathiazole (STZ), respectively. A solution of dimethylaminobenzaldehyde (DMAB) is added to the column eluate and the resulting sulfonamide- DMAB complex is detected at 450 nm. The method was tested for linearity, recovery, and precision across a broad sample range. Recovery was 100.6 ± 2.3% and 96.3 ± 1.6% for STZ and SMT, respectively. Linearity was excellent (r2 = 0.9985 for STZ and r2 = 0.9996 for SMT) as was within-day precision (RSD = 2.00% for STZ and 1.52% for SMT). The method was compared with the Bratton-Marshall colorimetric method. Analysis of 14 STZ and 15 SMT samples failed to detect any bias between the 2 methods. Some practical aspects of the use of this technique are discussed.
Differential Pulse Polarographic Determination of N-Nitrosodiethanolamine in Cosmetic Products
Authors: Chou Hardy J , Yates Ronald L , Gajan Raymond J , Davis Henry M 
Published: February 2020

Abstract
A differential pulse polarographic (DPP) method is described for the detection and determination of JV-nitrosodiethanolamine (NDELA) in cosmetic products. The cosmetic sample is partitioned between IN HC1 and chloroform. The aqueous extract is isolated and further purified by passing it through a cartridge containing reverse phase high pressure liquid chromatographic (HPLC) packing (C18 Sep- Pak). Samples containing proteins are cleaned up by gel permeation chromatography. Direct polarographic interferences are removed by preparative HPLC. The prepared samples are then analyzed by polarography using the method of standard additions for quantitation. The DPP method can be used to determine NDELA in cosmetic products at levels as low as 100 ppb. Analyses of a commercial lotion and a commercial cream spiked at 3 levels in the ppm range gave recoveries ranging from 73 to 91%. The average of all recoveries was 80%.
Gas Chromatographic Method for Determining Strychnine Residues in Alfalfa
Authors: Miller Glenn , Warren John , Gohre Kirk , Hanks Larry 
Published: February 2020

Abstract
A gas-liquid chromatographic procedure is described for determining strychnine in alfalfa with a nitrogen- phosphorus detector. Alfalfa samples containing strychnine residues are chopped and extracted in a blender using ethyl acetate, sodium carbonate, and sodium sulfate, and the organic extract is extracted with 0.1N H2SO4 solution, made basic, and subsequently extracted with methylene chloride. Following concentration, the strychnine residues are quantitated by peak height, using an external standard. Recoveries for 0.05 ppm spikes were 88 ± 11%.
Levels of Lead in the United States Food Supply
Authors: Jelinek Charles F 
Published: February 2020

Abstract
As a result of the Food and Drug Administration’s (FDA) concern about lead in the food supply, considerable data have been developed in recent years by FDA, other agencies, and industry on the levels of lead in foods. Data obtained on the lead content of milk, eggs, meat, fish, and shellfish indicate that the mean levels in these unprocessed foods varied from 0.02 to about 0.4 ppm, with the lowest level in milk. The major food processing source of lead in food is the lead-soldered can. FDA had assigned top priority to the reduction of lead in foods for infants because of their greater susceptibility to the toxic effects of this metal. The lead levels in foods for infants are now only 1/5 to 1/10 of what they were when FDA expressed its concern about lead to the manufacturers of canned infant formula, evaporated milk, canned infant juices, and glass-packed infant foods. FDA priority interest has now shifted to reduction of lead in adult canned foods, especially those eaten by young children. The mean levels in such foods have decreased from 0.35-0.40 ppm in 1974 to 0.20-0.25 ppm in 1980.
Certification of Lead Concentration in Standard Reference Materials by Isotope Dilution Mass Spectrometry
Authors: Barnes I Lynus , Murphy Thomas J , Michiels Eddy A I 
Published: February 2020

Abstract
In response to needs for analytical standards by researchers studying the exposure of humans to lead, a wide variety of environmental and “food” Standard Reference Materials have been prepared and certified for lead as well as for many other elements. Among the food types are SRM1571, Orchard Leaves, 45 ppm; SRM 1575, Pine Needles, 10.8 ppm; SRM 1573, Tomato Leaves, 6.3 ppm; SRM 1566, Oyster Tissue, 0.48 ppm; SRM 1577, Bovine Liver, 0.34 ppm; SRM 1568, Rice Flour, 0.045 ppm; and SRM 1567, Wheat Flour, 0.020 ppm. These materials, intended for use in calibrating instruments and methods, have been certified by a definitive method, isotope dilution mass spectrometry. The advantages and disadvantages of this technique are discussed and some suggestions for the use of its isotopic selectivity in the study of lead in the human environment are presented.
Determination of Lead and Cadmium in Foods by Anodic Stripping Voltammetry: I. Development of Method
Authors: Gajan Raymond J , Capar Stephen G , Subjoc Cheryl A , Sanders Marion 
Published: February 2020

Abstract
Food samples are dry ashed at 500 ± 50°C with a 10% aqueous K2SO4 solution used as an ashing aid. The ashed sample is dissolved in 50 mL 2% HNO3. Anodic stripping voltammetry is used to determine lead and cadmium in a mixture of the sample solution and an acetate electrolyte at pH 4.3 ± 0.3. The estimated quantitation limits, based on a 10 g food sample, are 0.005 ppm for cadmium and 0.010 ppm for lead.
Inhibition of Chlortetracycline Activity by Magnesium Ions
Authors: Chiang Tom 
Published: February 2020

Abstract
Up to 50% of the antimicrobial activity of chlortetracycline (CTC) can be inhibited by the presence of MgSC»4 in microbiological turbidimetric assays. From 50 to 200 mM MgS04 inhibited CTC activity, and the relationship between CTC inhibition and MgSC»4 concentration is linear. The possible mechanism of this inhibition and its potential implication are discussed.
Rapid Gas-Liquid Chromatographic Method for Determination of Sulfamethazine in Swine Feed
Authors: Munns Robert K , Roybal Jose E 
Published: February 2020

Abstract
A gas-liquid chromatographic method is described for the quantitative determination of trace amounts of sulfamethazine in swine feed. Sulfamethazine is extracted in ammoniated acetone and isolated from other extractants on a Sephadex LH-20 column. The eluate is methylated with diazomethane and evaporated to dryness. The residue is dissolved in a solvent containing an internal standard of methyl sulfasymazine before being injected onto an OV-25 GLC column. An estimation of precision was established by assaying 10 sets of swine feed fortified with 0.5, 1,2, and 5 ppm SMZ. Mean recoveries were 96.0,94.3, 93.5, and 94.0%, respectively, with an average coefficient of variation of 3.07%. The critical steps and ruggedness of the method were also determined.
Extraction Procedures for Oilseeds and Related High Fat-Low Moisture Products
Authors: Sawyer Leon D 
Published: February 2020

Abstract
A combined sample preparation/extraction procedure is presented for pesticide residue analysis of oilseeds and related high fat-low moisture products. The procedure utilizes high-speed milling to prepare the sample and high-speed homogenization in the extraction step to achieve what is apparently quantitative isolation of both incurred residues and natural oils. A separate, simple, oil determination step allows findings to be reported on either the fat or whole product basis. Petroleum ether, ethyl etherpetroleum ether (1 + 1), and ethanol are used serially as the extractants. Usual fatty food cleanup procedures and multiresidue gas chromatographic detection techniques are utilized. The procedure presented in this paper is a refinement of earlier work which used a homogenizer both to grind and to extract samples of unground seeds and which demonstrated essentially complete extraction of endrin residues in soybeans and DDT residues in mustard seed. Identical samples analyzed by the currently recommended shakeout procedure, 29.012, gave recoveries of approximately 50% of the total residues. The procedure presented in this paper was satisfactorily tested on 13 different oilseed types and one sample of soda crackers. Oil content for these samples ranged from 5 to 69%.
Use of Iron Milk Medium for Enumeration of Clostridium perfringens
Authors: John William D St , Matches Jack R , Wekell Marleen M 
Published: February 2020

Abstract
A simple iron milk medium was used for isolation and enumeration of Clostridium perfringens from soil, sludge, and water samples. The whole milk contained only iron powder as a reducing agent; no other inhibitors were added. The iron milk most probable number (MPN) procedure was compared with 4 plating media: sulfite-polymyxin-sulfadiazine, Shahidi-Ferguson perfringens, tryptose-sulfite- cycloserine (both with and without egg yolk), and tryptone-sulfite-neomycin. The selectivity of the iron milk relies solely on the rapid growth of C. perfringens at 45°C and the stormy fermentation reaction within 18 h. Isolates were confirmed as C. perfringens by standard biochemical tests. The iron milk MPN procedure compared very well with the 4 plating media tested. Selectivity of incubation temperature, short incubation time, and ease of identification by the characteristic stormy fermentation make this method ideal for enumerating C. perfringens from large numbers of samples.
Computer Utilization in the Food and Drug Administration's Bureau of Foods Mass Spectrometry Laboratory
Authors: Dreifuss Peter A , Dusold Laurence R 
Published: February 2020

Abstract
A network of computers is being used to support the Food and Drug Administration's Bureau of Foods mass spectrometry facility. Five mass spectrometers are each interfaced to at least 2 of the 6 dedicated minicomputers in the laboratory. This multiple interfacing provides data acquisition and processing backup, reducing the overall down-time. Selected data from all of the minicomputers can be sent to FDA's main computers via a digital cartridge tape recorder or paper tape. The digital cartridge tape recorder records data that are output from a minicomputer terminal and then plays it back on a terminal which is on-line with the main computer. This main computer stores and edits data; plots spectra for reports, data banks, and publications; and carries out some data processing. Multiple interfacing also serves to supplement the capabilities of the 8-year-old Finnigan MAT (formerly Varian MAT) SS-100 data system (Sperry-Univac/V-76) with the newer and more powerful Finnigan MAT INCOS (Data General/Nova 3) data system. The SS-100 data system is also enhanced by the substitution of the 110 baud paper tape with a 9600 baud cartridge tape recorder for I/O of system bootstraps, BASIC programs, and raw data.
Ion-Pair High Performance Liquid Chromatographic Separation and Detection of Subsidiary Dyes in Synthetic Food Colors
Authors: Lancaster Frank E , Lawrence James F 
Published: February 2020

Abstract
A high performance liquid chromatographic method utilizing a reverse phase ion-pair technique is presented for separating subsidiary dyes from commercial samples of Amaranth, Sunset Yellow FCF, and Tartrazine. After separation, the subsidiaries or primary dyes are quantitated by using known standards. Recoveries of subsidiaries, l-(4-sulfo-l-naphthylazo)- 2-naphthol-6-sulfonic acid, disodium salt from Amaranth; l-p-sulfophenylazo-2-naphthol- 3,6-disulfonic acid, trisodium salt from Sunset Yellow FCF; 3-carboxy-5-hydroxy-l-p-sulfophenyl-4-phenylazo-pyrazole, disodium salt from Tartrazine, ranged from 92 to 102% at the spiking levels studied (0.06-16%, depending on the subsidiary). The method was successfully applied to the analysis of commercial samples.
Dual Column Chromatographic Method for Determination of N-Nitrosothiazolidine in Fried Bacon
Authors: Pensabene John W , Fiddler Walter 
Published: February 2020

Abstract
A dual column chromatographic procedure is described that permits the determination of N-nitrosothiazolidine (NTHZ), a newly identified nitrosamine, and N-nitrosopyrrolidine (NPYR), the principal volatile nitrosamine, in the same fried bacon sample. The procedure used an acid-Celite, Celite, sodium sulfate column followed by a partially deactivated basic alumina column to isolate NTHZ from bacon for subsequent quantitation by gas chromatography with a thermal energy analyzer (GC-TEA). A limited intralaboratory study gave standard deviations for repeatability and reproducibility of 1.20 and 1.55 ppb, respectively. The recovery of N-nitrosothiomorpholine, the internal standard added at the 10 ppb level, was 93.3 ± 6.03%. The method is also free from artifactual nitrosamine formation.
High Pressure Liquid Chromatographic Determination of Allantoin in Cosmetic Creams and Lotions
Authors: Nakao Kazuo , Honda Keiichi , Yoneya Tohru 
Published: February 2020

Abstract
A sensitive high pressure liquid chromatographic method was developed for the determination of allantoin in cosmetic preparations. The procedure consists of simple cleanup of samples, derivatization with p-nitrobenzaldehyde in N,N-dimethylformamide to an ultraviolet labeled derivative, and reverse phase chromatography on an octadecylsilylated silica column. Ultraviolet absorbance was measured at 270 nm. Recovery was greater than 97% for cosmetic samples, and the minimum limit of detection was 10 ng.
Gas Chromatographic Determination of the Captan Metabolite Tetrahydrophthalimide in Urine
Authors: Schoen Sarah R , Winterlin Wray L 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method is described for the determination of the captan metabolite tetrahydrophthalimide in human urine. The sample is extracted with chloroform and cleaned up on a Florisil column. The extract is then analyzed by GLC, using a nitrogen-phosphorus-selective detector. Recoveries from urine samples fortified at 0.03-0.5 ppm ranged from 82 to 87%, and were qualitatively confirmed by GLC-mass spectrometry.
Gas Chromatographic and Gas Chromatographic-Mass Spectrometric Confirmation of 2,4- and 2,6-Toluenediamine Determined by Liquid Chromatography in Aqueous Extracts
Authors: Snyder Roger C , Brumley William C , Breder Charles V , Fazio Thomas 
Published: February 2020

Abstract
The confirmation of 2,4- and 2,6-toluenediamine (TDA) in aqueous extracts from boil-in-bags and retortable pouches is described. The extracts were initially analyzed by a high performance liquid chromatographic procedure and any apparent 2,4- and/or 2,6-TDA were quantitated. The liquid chromatographic effluent corresponding to any apparent 2,4- or 2,6-TDA was collected. TDA was then partitioned into ethyl acetate and reacted with trifluoroacetic anhydride (TFAA). The TDA-TFAA derivative formed was confirmed by gas-liquid chromatography (GLC) using a 1.2 m × 0.32 cm nickel column packed with 6% OV-17 on Superpak-20M. Results obtained from analyzing extracts of several retortable pouches and boil-in-bags showed levels of TDA migration ranging from &lt;0.1 to 2.2 ppb (μg/L). Additional confirmation of the TDA-TFAA derivative from retortable pouches by multiple ion detection GC/mass spectrometry is also described.
High Performance Liquid Chromatography with Fluorescence and Ultraviolet Detection of Polynuclear Aromatic Hydrocarbons in Barley Malt
Authors: Joe Frank L , Salemme Jean , Fazio Thomas 
Published: February 2020

Abstract
A simple, rapid method has been developed for the separation and determination of polynuclear aromatic hydrocarbons (PAHs) in barley malt. An ultrasonic- cyclohexane extraction method was used to separate the PAHs from ground barley malt. The cyclohexane extracts were purified by chromatography through a water-deactivated silica gel-alumina column. The eluate from the column was concentrated and purified further by partitioning between dimethyl sulfoxide (DMSO) and cyclohexane. The DMSO extract was diluted with water and the PAHs were extracted back into cyclohexane. The cyclohexane extract was washed with water, dried through sodium sulfate, and evaporated, and the resulting residue was dissolved in 80% aqueous acetonitrile-methanol (1 + 1) and subjected to reverse phase high performance liquid chromatography. Thirty barley malt samples were analyzed using this procedure. Peaks having the same retention time as the carcinogen benzo(a)pyrene were isolated from 18 of the samples, and were equivalent to trace levels ranging from &lt;0.1 to 0.2 ppb. Average recoveries of 11 PAHs, including benzo(a)pyrene, benzo(b)fluoranthene, indeno(l,2,3-cd)pyrene, and benz(a)anthracene, added to 25 g samples at 2.5 and 5 ppb, ranged from 78 to 97%, with a mean relative standard deviation of 6.6%.
Detection of Adulteration in Blackberry Juice Concentrates and Wines
Authors: Wrolstad Ronald E , Culbertson Jeffrey D , Corn Well Christopher J , Mattick Leonard R 
Published: February 2020

Abstract
Adulteration of blackberry juice concentrates and wines with juice of sorbitol-containing fruits was detected by determining carbohydrates by high performance liquid chromatography, gas-liquid chromatography, and thin layer chromatography. Sorbitol is not fermented by yeast and can be detected in wines made from blackberry juice concentrates that contain sorbitol. High levels of sorbitol and quinic and malic acids suggest that an imported blackberry concentrate may have been adulterated with plum. Degradation of anthocyanin pigments during processing and storage limits the utility of pigment analyses in detecting adulteration.
Infant Formula Label Review
Authors: Barnes Roger W 
Published: February 2020

Abstract
The FDA review of infant formula labeling was conducted by a multi-disciplinary team composed of physicians, scientists, and experts in regulations and labeling. The review followed 2 tracks: the development of a general position of what would be necessary if we started with a blank label; and the purchase of many formulas and a critical review of information on the labels. An important part of the review was determining what information was available in the literature and using this information in assessing current practices and the effectiveness of present labeling. The review was divided into several major topics: introduction, definitions, historical perspectives, current regulatory situation, effectiveness of labeling, label review, other issues, and departmental initiatives. The labels review included product attributes, shelf life, retail and home storage instructions, and consumer preparation and use.
Proximate and Elemental Analysis of Infant Formula
Authors: Tanner James T 
Published: February 2020

Abstract
The Nutrient Surveillance Branch has been conducting a survey of infant formula products for Fiscal Year 1981. Each product has been carefully analyzed and the results compared to the label declaration and the minimum-maximum limits specified by the American Academy of Pediatrics’ Committee on Nutrition (CON/AAP). Proximate and elemental analyses were made. Protein, fat, ash, and total solids (moisture) were determined by AOAC methods. Osmolality, density, and fatty acids (linoleic) were also determined. Carbohydrates were calculated by difference and caloric content was calculated by using the general Atwater factors. Elemental analysis for Ca, P, Mg, Fe, Zn, Cu, Mn, Na, and K were performed by induction coupled plasma absorption spectroscopy. Chloride was assayed by potentiometric titration with AgNC3. A summary of the findings from the infant formula survey have been compared with CON/AAP recommendations. In general, there were only a few exceptions where the label claims and the CON/AAP requirements were not met. However, in none of these cases was the difference considered to be of public health significance.
Infant Food Problems and Analytical Aspects of Providing Safe and Wholesome Infant Foods
Authors: Read R B 
Published: February 2020

Abstract
The technology of milk and infant food production, storage, and handling has advanced to the point that infant foods have had an excellent record of being free of recognized health hazards. The Infant Formula Council has published methods specifically for these foods. Methods are included from Standard Methods for the Examination of Dairy Products, Official Methods of Analysis, Bacteriological Analytical Manual, the Manual of Clinical Microbiology, and the U.S. Pharmacopeia. Criteria for microbiological quality have been issued by the Codex Alimentarius Commission, the International Commission for Microbiological Specifications for Foods, and the Public Health Service. Surveys in the United States and Canada have shown that sanitary standards are met with ease.