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Maximum Residue Limit
The maximum residue limit (also maximum residue level, MRL), is the maximum amount of pesticide residue that is expected to remain on food products when a pesticide is used according to label directions, that will not be a concern to human health. Determination The MRL is usually determined by repeated (on the order of 10) field trials, where the crop has been treated according to good agricultural practice (GAP) and an appropriate pre harvest interval or withholding period has elapsed. For many pesticides this is set at the Limit of determination (LOD) – since only major pesticides have been evaluated and understanding of acceptable daily intake (ADI) is incomplete (i.e. producers or public bodies have not submitted MRL data – often because these were not required in the past). LOD can be considered a measure of presence/absence, but certain residues may not be quantifiable at very low levels. For this reason the limit of quantification (LOQ) is often used instead of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pesticide
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampricide. The most common of these are herbicides which account for approximately 80% of all pesticide use. Most pesticides are intended to serve as plant protection products (also known as crop protection products), which in general, protect plants from weeds, fungi, or insects. As an example, the fungus ''Alternaria solani'' is used to combat the aquatic weed ''Salvinia''. In general, a pesticide is a chemical (such as carbamate) or biological agent (such as a virus, bacterium, or fungus) that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, or spread disease, or a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Good Agricultural Practice
Good agricultural practice (GAP) is a certification system for agriculture, specifying procedures (and attendant documentation) that must be implemented to create food for consumers or further processing that is safe and wholesome, using sustainable methods. While there are numerous competing definitions of what methods constitute good agricultural practice, there are several broadly accepted schemes that producers can adhere too. Motivation Introduction of GAP is particularly desirable when there is chronic overuse and misuse of agricultural pesticides. Governments seek to reduce the use of pesticides by promoting alternative methods of pest management, while at the same time ensuring a steady production of safe and wholesome food. Organizations Food and Agricultural Organization (FAO) of the United Nations GAP The Food and Agricultural Organization of the United Nations (FAO) uses good agricultural practice as a collection of principles applying to on-farm production and po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detection Limit
The limit of detection (LOD or LoD) is the lowest signal, or the lowest corresponding quantity to be determined (or extracted) from the signal, that can be observed with a sufficient degree of confidence or statistical significance. However, the exact threshold (level of decision) used to decide when a signal significantly emerges above the continuously fluctuating background noise remains arbitrary and is a matter of policy and often of debate among scientists, statisticians and regulators depending on the stakes in different fields. Significance in analytical chemistry In analytical chemistry, the detection limit, lower limit of detection, or LOD (limit of detection), often mistakenly confused with the analytical sensitivity, is the lowest quantity of a substance that can be distinguished from the absence of that substance (a '' blank value'') with a stated confidence level (generally 99%). The detection limit is estimated from the mean of the blank, the standard deviation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acceptable Daily Intake
Acceptable daily intake or ADI is a measure of the amount of a specific substance (originally applied for a food additive, later also for a residue of a veterinary drug or pesticide) in food or drinking water that can be ingested (orally) daily over a lifetime without an appreciable health risk. ADIs are expressed usually in milligrams (of the substance) per kilograms of body weight per day. History This concept was first introduced in 1961 by the Council of Europe and later, the Joint FAO/WHO Expert Committee on Food Additives (JECFA), a committee maintained by two United Nations bodies: the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). Concept An ADI value is based on current research, with long-term studies on animals and observations of humans. First, a no-observed-adverse-effect level (NOAEL), the amount of a substance that shows no toxic effects, is determined. Usually the studies are performed with several doses including high doses. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limit Of Quantification
The limit of detection (LOD or LoD) is the lowest signal, or the lowest corresponding quantity to be determined (or extracted) from the signal, that can be observed with a sufficient degree of confidence or statistical significance. However, the exact threshold (level of decision) used to decide when a signal significantly emerges above the continuously fluctuating background noise remains arbitrary and is a matter of policy and often of debate among scientists, statisticians and regulators depending on the stakes in different fields. Significance in analytical chemistry In analytical chemistry, the detection limit, lower limit of detection, or LOD (limit of detection), often mistakenly confused with the analytical sensitivity, is the lowest quantity of a substance that can be distinguished from the absence of that substance (a '' blank value'') with a stated confidence level (generally 99%). The detection limit is estimated from the mean of the blank, the standard deviation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocoa Bean
The cocoa bean (technically cocoa seed) or simply cocoa (), also called the cacao bean (technically cacao seed) or cacao (), is the dried and fully fermented seed of ''Theobroma cacao'', from which cocoa solids (a mixture of nonfat substances) and cocoa butter (the fat) can be extracted. Cocoa beans are the basis of chocolate, and Mesoamerican foods including tejate, an indigenous Mexican drink that also includes maize, and pinolillo, a similar Nicaraguan drink made from a cornmeal & cocoa powder. Etymology The word ''cocoa'' comes from the Spanish word , which is derived from the Nahuatl word . The Nahuatl word, in turn, ultimately derives from the reconstructed Proto-Mixe–Zoquean word ''kakawa''. Used on its own, the term ''cocoa'' may also mean: * Hot cocoa, the drink more known as ''hot chocolate'' Terms derived from ''cocoa'' include: * Cocoa paste, ground cocoa beans: the mass is melted and separated into: ** Cocoa butter, a pale, yellow, edible fat ** Cocoa s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Factor
In engineering, a factor of safety (FoS), also known as (and used interchangeably with) safety factor (SF), expresses how much stronger a system is than it needs to be for an intended load. Safety factors are often calculated using detailed analysis because comprehensive testing is impractical on many projects, such as bridges and buildings, but the structure's ability to carry a load must be determined to a reasonable accuracy. Many systems are intentionally built much stronger than needed for normal usage to allow for emergency situations, unexpected loads, misuse, or degradation (reliability). Definition There are two definitions for the factor of safety (FoS): * The ratio of a structure's absolute strength (structural capability) to actual applied load; this is a measure of the reliability of a particular design. This is a calculated value, and is sometimes referred to, for the sake of clarity, as a ''realized factor of safety''. * A constant required value, imposed by law, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pesticides
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampricide. The most common of these are herbicides which account for approximately 80% of all pesticide use. Most pesticides are intended to serve as plant protection products (also known as crop protection products), which in general, protect plants from weeds, fungi, or insects. As an example, the fungus ''Alternaria solani'' is used to combat the aquatic weed ''Salvinia''. In general, a pesticide is a chemical (such as carbamate) or biological agent (such as a virus, bacterium, or fungus) that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, or spread disease, or ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QuEChERS
QuEChERS is a solid phase extraction method for detection of pesticide residues in food. The name is a portmanteau word formed from "quick, easy, cheap, effective, rugged, and safe". Technique The sample (fruits, vegetables, tobacco, etc.) is homogenized and centrifuged with a reagent and agitated for 1 minute. The reagents used depend on the type of sample to be analyzed. Following this, the sample is put through a dispersive solid phase extraction cleanup prior to analysis by gas-liquid chromatography Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, ... or liquid-liquid chromatography. Samples prepared using the QuEChERS method can be processed more quickly using a homogenization instrument. Such instruments can homogenize the food sample in a centrifuge tube, then agitate the sampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Contamination
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons (such as naphthalene and benzo(a)pyrene), solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapour from the contaminants, or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting cleanups are time-consuming and expensive tasks, and require expertise in geology, hydrology, chemistry, compute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
