Sampling and Sample Preparation for Detection and Quantitation of Natural Toxicants in Food and Feed

1989 ◽  
Vol 72 (3) ◽  
pp. 399-404 ◽  
Author(s):  
Douglas L Park ◽  
Albert E Pohland
Keyword(s):  
Sample Preparation ◽  
Test Sample ◽  
Sampling Procedure ◽  
Sampling Plan ◽  
Representative Sampling ◽  
Factors Affecting ◽  
Natural Toxins ◽  
Continuous Stream ◽  
Food And Feed ◽  
Representative Samples

Abstract The primary goal of a sampling plan for natural toxins, i.e., mycotoxins and seafood toxins, is to obtain a sample that accurately represents the concentrations of individual components of a given lot. Factors affecting the ability of the sampling plan to accomplish this goal include: (1) nature of the analyte of interest; (2) distribution of the analyte throughout the lot, (3) physical characteristics of the product, (4) accessibility of the product to random representative sampling, (5) sampling procedure, and (6) size of sample. Sampling plans are composed of 3 distinct components: (a) sampling, (b) sample preparation, and (c) analysis. Normally, sampling contributes the largest relative error while analysis comprises the least. Automatic, continuous stream samplers provide the most representative samples for commodities such as nuts, cottonseed, and cereal grains. Good sample preparation equipment is currently available for these commodities; the use of this equipment to obtain a representative test sample is discussed.

Application of Automated FIB for TEM Sample Preparation in Semiconductor Failure Analysis

2014 ◽  
Author(s):  
Jie Zhu ◽  
Soo Sien Seah ◽  
Irene Tee ◽  
Bing Hai Liu ◽  
Eddie Er ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Success Rate ◽  
Protective Layer ◽  
Factors Affecting ◽  
Dual Beam ◽  
Lamella Thickness ◽  
Surface Patterns ◽  
Working Parameters ◽  
Practical Factors ◽  
High Flexibility

Abstract In this paper, we describe automated FIB for TEM sample preparation using iFast software on a Helios 450HP dual-beam system. A robust iFast automation recipe needs to consider as many variables as possible in order to ensure consistent sample quality and high success rate. Variations mainly come from samples of different materials, structures, surface patterns, surface topography and surface charging. The recipe also needs to be user-friendly and provide high flexibility by allowing users to choose preferable working parameters for specific types of samples, such as: grounding, protective layer coating, milling steps, and final TEM lamella thickness/width. In addition to the iFast recipe, other practical factors affecting automation success rate are also discussed and highlighted.

Developments in mycotoxin analysis: an update for 2012-2013

2014 ◽  
Vol 7 (1) ◽  
pp. 3-33 ◽  
Author(s):  
F. Berthiller ◽  
P.A. Burdaspal ◽  
C. Crews ◽  
M.H. Iha ◽  
R. Krska ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Sample Preparation ◽  
Ergot Alkaloids ◽  
Tandem Mass ◽  
Wide Range ◽  
Rapid Spread ◽  
Food And Feed ◽  
Mycotoxin Analysis ◽  
The Individual

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2012 and mid-2013. It covers the major mycotoxins: aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes and zearalenone. A wide range of analytical methods for mycotoxin determination in food and feed were developed last year, in particular immunochemical methods and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS)-based methods. After a section on sampling and sample preparation, due to the rapid spread and developments in the field of LC-MS/MS multimycotoxin methods, a separate section has been devoted to this area of research. It is followed by a section on mycotoxins in botanicals and spices, before continuing with the format of previous reviews in this series with dedicated sections on method developments for the individual mycotoxins.

scholarly journals Factors Affecting Spermatozoa Motility Analysis using CASA

2019 ◽  
Vol 29 (3) ◽  
pp. 145
Author(s):  
Dian Ratnawati ◽  
N Isnaini ◽  
T Susilawati
Keyword(s):  
Sample Preparation ◽  
Influencing Factors ◽  
Frame Rate ◽  
Analysis Time ◽  
Factors Affecting ◽  
Spermatozoa Motility ◽  
Fast Implementation ◽  
Concentration Chamber

Motility is a very important parameter to determine the quality of semen. Spermatozoa motility assessment can be done manually (subjectively) or with CASA. The superiority of motility assessment using CASA compared to manually is more objective, accurate, fast, efficient and able to provide detailed motility of spermatozoa. However, in implementation, assessments with CASA produce varied data. So far, there has not been a spermatozoa motility standard with CASA, except by minimizing variations in the factors that influence the results of analysis with CASA. The purpose of this paper is to describe factors that affecting spermatozoa motility analysis using CASA to reach optimal motility analysis. Some influencing factors include: CASA settings, semen diluent, spermatozoa concentration, chamber, analyst, sample preparation and analysis time. Recommendation standard motility assessments using CASA include: experienced and consistent analysts, sample preparation properly (mixing, pipeting and sampling), spermatozoa concentration of 20 million / ml, consistent in chamber type (conditioned 37°C), semen diluents and CASA settings (frame rate of 60 Hz and frame per field 30) and fast implementation of analysis (<2 minutes).

Assessing the wear characteristics of aggregate exposed at the road surface

1998 ◽  
Vol 13 (1) ◽  
pp. 149-157
Author(s):  
A. R. Woodside ◽  
W. D. H. Woodward
Keyword(s):  
Sample Preparation ◽  
Historical Development ◽  
Test Sample ◽  
Test Methods ◽  
Road Surface ◽  
Wear Characteristics ◽  
Density Correction ◽  
The Road ◽  
Rock Types

AbstractThis paper considers the assessment of highway surfacing aggregate wear using the Aggregate Abrasion Value and micro-Deval test methods. Their historical development is discussed. The influence of test sample preparation and number of chippings assessed is compared. Data for both methods are presented for a range of rock types. Dry, wet and soaked versions of the micro-Deval test are compared. The use of a density correction to modify the micro-Deval test value is proposed. The ability of the Aggregate Abrasion Value and micro-Deval test methods to assess heterogeneous aggregates is assessed.

Changes in the electrical conductivity of glass, quartz, Au, C, and MoS2 films under influence of continuous proton injection

2021 ◽  
Vol 10 ◽  
pp. 37-46
Author(s):  
G. S. Burkhanov ◽  
◽  
S. A. Lachenkov ◽  
M. A. Kononov ◽  
A. U. Bashlakov ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Ion Beam ◽  
Test Sample ◽  
Ion Source ◽  
Gold Target ◽  
Glass Substrates ◽  
Wide Range ◽  
Continuous Stream ◽  
Conductivity Of Thin Films

Changes in the electrical conductivity of a wide range of materials with different crystal-chemical types and electrophysical properties (quartz, glass, molybdenum disulfide, graphite, gold) under continuous proton injection are studied. Film samples of layered MoS2 and graphite compounds were obtained on rough surfaces of glass or quartz by mechanical rubbing of powder. Gold films are formed on glass substrates by magnetron sputtering of a gold target. To create a continuous stream of protons injected into the test sample, a stationary ion source with a cold cathode and a magnetic field forming an ion beam of relatively low intensity was used. The current in the ion beam is up to 1.2 mA, the pressure of hydrogen in the chamber is ~10 – 2 Pa, the energy of hydrogen ions is from 1 to 4 keV. The experimental results indicate that under conditions of continuous proton injection, the electrical conductivity of thin films with a layered structure (MoS2 and graphite) increases sharply (by 4 – 5 orders of magnitude). This effect increases when the temperature decreases from ~ 293 to ~ 77 K, as well as when the number of charges supplied to the sample increases. In the case of continuous injection of protons into massive dielectrics (glass, quartz) and thin films of gold, no noticeable change in electrical conductivity was detected.

scholarly journals Physicochemical Characterization of the Pristine E171 Food Additive by Standardized and Validated Methods

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 592 ◽  
Author(s):  
Eveline Verleysen ◽  
Nadia Waegeneers ◽  
Frédéric Brassinne ◽  
Sandra De Vos ◽  
Isaac Ojea Jimenez ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Particle Size ◽  
Sample Preparation ◽  
Inductively Coupled Plasma ◽  
Physicochemical Characterization ◽  
Intestinal Barrier ◽  
Food Additive ◽  
Crystallographic Structure ◽  
The European Union ◽  
Representative Samples

E171 (titanium dioxide) is a food additive that has been authorized for use as a food colorant in the European Union. The application of E171 in food has become an issue of debate, since there are indications that it may alter the intestinal barrier. This work applied standardized and validated methodologies to characterize representative samples of 15 pristine E171 materials based on transmission electron microscopy (TEM) and single-particle inductively coupled plasma mass spectrometry (spICP-MS). The evaluation of selected sample preparation protocols allowed identifying and optimizing the critical factors that determine the measurement of the particle size distribution by TEM. By combining optimized sample preparation with method validation, a significant variation in the particle size and shape distributions, the crystallographic structure (rutile versus anatase), and the physicochemical form (pearlescent pigments versus anatase and rutile E171) was demonstrated among the representative samples. These results are important for risk assessment of the E171 food additive and can contribute to the implementation of the European Food Safety Authority (EFSA) guidance on risk assessment of the application of nanoscience and nanotechnologies in the food and feed chain.

What about the 'other' Fusarium mycotoxins?

2009 ◽  
Vol 2 (2) ◽  
pp. 181-192 ◽  
Author(s):  
M. Jestoi ◽  
M. Kokkonen ◽  
S. Uhlig
Keyword(s):  
Current Knowledge ◽  
Fusarium Species ◽  
Animal Health ◽  
Natural Occurrence ◽  
Fusarium Mycotoxins ◽  
Fusarium Spp ◽  
Natural Toxins ◽  
Toxic Metabolites ◽  
Food And Feed ◽  
Very High

Most Fusarium species are capable of producing mycotoxins that may cause adverse effects on human or animal health. The most commonly studied Fusarium mycotoxins include trichothecenes, zearalenone and fumonisins. However, it seems that nearly all of the most prevalent Fusarium species infecting grains are also capable of producing other toxic metabolites. The existing studies, although exiguous, have clearly demonstrated that other toxic metabolites of Fusarium spp. are also present in our foods and feeds, occasionally at very high levels. It is apparent that since mycotoxins, including these 'other' metabolites, are natural toxins, they cannot be completely eliminated from food and feed chains. However, scientific studies are needed to determine their true significance. Thus, the mechanism and level of toxicity as well as presence and concentration levels will have to be fully clarified. In this paper, we briefly review the prevalence of the dominant Fusarium species contaminating maize and small-grain cereals worldwide, and the current knowledge on the biological activity as well as the natural occurrence of their selected less-known toxic metabolites. Additionally, the significance of these 'other' Fusarium mycotoxins is discussed.

scholarly journals Increased knowledge predicts greater adherence to the Mediterranean diet in Greek adolescents

2009 ◽  
Vol 12 (2) ◽  
pp. 208-213 ◽  
Author(s):  
Paraskevi K Tsartsali ◽  
Janice L Thompson ◽  
Russell Jago
Keyword(s):  
Family Income ◽  
Dietary Habits ◽  
Vegetable Consumption ◽  
Economic Status ◽  
Sampling Procedure ◽  
Normal Weight ◽  
Cross Sectional ◽  
Factors Affecting ◽  
Westernized Diet ◽  
The Mediterranean

AbstractObjectivesTo examine knowledge of and adherence to the Mediterranean dietary pattern (MDP) among Greek adolescents, assess associations between MDP knowledge and adherence with BMI, and determine socio-cultural factors predicting MDP compliance.DesignCross-sectional.SettingGreek adolescents aged 15–17 years.SubjectsTwo hundred adolescents (103 females, ninety-seven males) from six schools on the Greek island of Chios. The sampling procedure was similar for all schools; schools were randomly selected from different geographic areas and all municipalities. BMI was calculated from measured height and weight; participants completed four questionnaires assessing parents’ socio-economic status and education, adolescents’ perceived and actual MDP knowledge, past-week dietary habits, and MDP adherence.ResultsParticipants’ BMI indicated 64·5 % were normal weight and 35·5 % were overweight/obese (mean BMI 23·7 (sd 3·8) kg/m2). Over half had very poor MDP knowledge (58·5 %) and adherence (59·5 %); both perceived (F = 3·35, P = 0·037) and actual MDP knowledge (F = 3·45, P = 0·034) were significantly different across MDP adherence. Perceived MDP knowledge was positively correlated with vegetable consumption (r = 0·185, P = 0·009); actual knowledge was negatively correlated with meat consumption (r = −0·191, P = 0·007). BMI was negatively correlated with family income (r = −0·202, P = 0·004), indicating higher BMI in less affluent households. Actual MDP knowledge was the only significant predictor of MDP adherence (standardized β = 0·162, P = 0·030) in a model accounting for 7·3 % of overall variance.ConclusionsGreek adolescents reported consuming a more Westernized diet detached from the traditional MDP. Actual MDP knowledge and family income were important factors affecting MDP adherence and BMI, respectively. Promoting the traditional MDP among Greek adolescents and their families appears warranted.

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