Chemical harvest acids

An estimation of the amount of amino acid production and the production methods are shown ia Table 11. About 340,000 t/yr of L-glutamic acid, principally as its monosodium salt, are manufactured ia the world, about 85% ia the Asian area. The demand for DL-methionine and L-lysiae as feed supplements varies considerably depending on such factors as the soybean harvest ia the United States and the anchovy catch ia Pern. Because of the actions of D-amiao acid oxidase and i.-amino acid transamiaase ia the animal body (156), the D-form of methionine is as equally nutritive as the L-form, so that DL-methionine which is iaexpensively produced by chemical synthesis is primarily used as a feed supplement. In the United States the methionine hydroxy analogue is partially used ia place of methionine. The consumption of L-lysiae has iacreased ia recent years. The world consumption tripled from 35,000 t ia 1982 to 100,000 t ia 1987 (214). Current world consumption of L-tryptophan and i.-threonine are several tens to hundreds of tons. The demand for L-phenylalanine as the raw material for the synthesis of aspartame has been increasing markedly. 

Monosodium methanearsonate (MSMA) [2163-80-6] CH AsONaOOH, disodium methanearsonate (DSMA) [144-21-8], CH2AsO(NaO)2, cacodyhc acid [75-60-5], (CH2)2AsOOH, and arsenic acid [7778-39-4], H AsO, are used ia agriculture appHcations (11,12). MSMA, DMSA, and cacodyUc acid are used as herbicides (qv) especially ia cotton (qv) fields for the control of Johnson and nutsedge grass and other weeds. Arsenic acid (13) and cacodyhc acid may be used as a desiccant for the defoHation of the cotton boU prior to harvesting. Calcium arsenate [7778-44-1], Ca2(As0 2> once an important chemical for the control of the boU weevil and cotton worm, has disappeared from appHcation and the use of lead arsenate [7784-40-9], Pb AsO, for fmit crops is currentiy restricted. 

Chono, M., I. Honda et al. (2006). Field studies on the regulation of abscisic acid content and germinability during grain development of barley Molecular and chemical analysis of pre-harvest sprouting. J. Exp. Bot. 57(10) 2421-2434. 

As pointed out earlier, all U.S. cotton in commercial production is now harvested by machines. The application of harvest-aid chemicals to cause the plants to shed their leaves (defoliation) or to kill and dry the plant (desiccation) are common practices in many areas. Chlorates and organic phosphates are popular defoliant materials and arsenic acid is commonly used as a desiccant. 

Many other compounds have been included in studies on sucrose response. Most of these have been herbicides or enzyme poisons. None of the common herbicides had any positive effect on sucrose at rates up to that causing severe foliar injury. Earlier reports of response from 2-(2,4,5-trichlorophenoxy)propionic acid and 2,2-dichloropropionic acid could not be substantiated in British Guiana and Queensland. 27 Some compounds, such as 3-(p-chlorophenyl)-l,l-dimethylurea (monuron), (2,4-dichloro-phenoxy) acetic acid in soil, ethylenediaminetetraacetic acid, and leaf desiccants decreased sucrose and juice solids content. 20 Field trials with several chemicals in Trinidad showed enhanced sucrose at 14 to 28 days before harvest resulting from the application of 8 and 12 lb. (per acre) of... 

Codeine is extracted from opium. Opium is a chemically complex drug derived from a flowering plant, the opium poppy. The scientific name for the opium poppy is Papaver somniferum, which translated from Greek means poppy that causes sleep. Opium is produced by drying the thick liquid harvested from the unripe seed capsule of the flower. It contains several different medically important chemicals known as alkaloids (non-acidic chemicals), the most important being morphine and codeine. 

More than 400 chemical compounds have been identified in marijuana. Approximately 60 of these are unique to the cannabis plant, substances called cannabinoids. Of the cannabinoids, a group of isomers (chemically similar substances) called tetrahydro-cannabinols (THC) are thought to be the most psychoactive. These are Ai-THC (also called A9-THC) and A6-THC (also called A8-THC). Other cannabinoids include cannabidiolic acid (CBDA), cannabidiol (CBD), and cannabinol (CBN). Their role in marijuana intoxication is less well understood. The amount of THC produced depends on the strain of cannabis and on environmental factors such as growth, harvest, and storage conditions. 

Most foods contain enzymes or natural chemicals, such as acids or alcohols, that cause them to begin to lose desirable characteristics almost immediately after harvest or preparation. In addition, a host of environmental factors, such as heat and the presence of microorganisms, acts to change... 

For these studies cells must be harvested mechanically, e.g. by scraping with a rubber policeman or by the use of chemicals (e.g. alkali, acid or detergent) which lead to instantaneous death of the cells from which various products may then be isolated. 

The ratio of a sample is measured in relation to a standard to improve the accuracy and precision of accelerator mass spectrometry measurements (Elmore and Phillips, 1987). Multiplying the ratio by 1000 results in the delta (del) values having units of parts per thousand, also know as per mil (%o). For standards, it is necessary to use wood from trees harvested before about 1850 pre-industrial, to avoid the Suess effects. The standard value for pre-industrialized atmospheric CO2 is 13.56 dpm g-1 or 14C/C equals 1.176 x 10-12 (Broecker and Peng, 1982). A correction term involving the effects of isotopic fractionation (IF) are also subtracted out of this equation. Isotopes are fractionated due to physical and chemical reactions (more details in the following section), thereby making the abundance of carbon isotopes (12C, 13C, and 14C) different in plants (Faure, 1986). The National Bureau of Standards currently provides an oxalic acid 14C standard that is used for this correction however, there have been many problems associated with development of this standard (Craig, 1954, 1961 Stuiver and Polach, 1977). 

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