Contents 1 Detergents

The RNA samples are dissolved in any buffer, the ionic strength of which has to be between 0.01 and 0.2 and which may content detergents. 

In the cleaning process the soil is removed by either batch or bath operation. These operations differ in solvent circulation, moisture content, detergent type, and length of wash time. The batch operation uses a fixed quantity of solvent for one operation. The solvent is not circulated during the wash cycle, while it is in the bath method. The bath operation is also known as the charged system. In the bath system, 1% to 4% concentrations of detergent and water are added into the wash tank. 

Detergents may be produced by the chemical reaction of fats and fatty acids with polar materials such as sulfuric or phosphoric acid or ethylene oxide. Detergents emulsify oil and grease because of their abiUty to reduce the surface tension and contact angle of water as well as the interfacial tension between water and oil. Recent trends in detergents have been to lower phosphate content to prevent eutrification of lakes when detergents are disposed of in municipal waste. 

The commercial product has an active oxygen content of at least 15%. This product has replaced the hexahydrate in some household detergents and other domestic products because it dissolves faster and has a greater content of active oxygen per unit volume of granular product. 

The quahty of sulfonic acids produced as iatermediates on an iadustrial scale is important to detergent manufacturers. Parameters such as color, water, free oil (unsulfonated material), and acid value (actual sulfonic acid) are all factors that determine the quaUty of a sulfonic acid. The quaUty of the feedstock prior to sulfonation, such as iodine value, water content, and sulfonatabiUty, affects the quaUty of the sulfonic acid produced. Sulfonation conditions, such as temperature, molar ratio, rate, etc, also affect the quaUty of sulfonic acid. 

Grease Refining and Fractionation. Lanolin to be used in pharmaceuticals and cosmetics must conform to strict requirements of purity, such as those in the U.S. and British Pharmacopoeias (181,182). These include specifications for the maximum allowable content of free fatty acids, moisture, ash, and free chloride. Lanolin intended for certain dermatological appHcations may have to meet further specifications in relation to free-alcohol and detergent contents (183,184). 

Chlorosulfuric acid attacks brass, bronze, lead, and most other nonferrous metals. From a corrosion standpoint, carbon steel and cast Hon are acceptable below 35°C provided color and Hon content is not a concern. Stainless steels (300-series) and certain aluminum alloys are acceptable materials of constmction, as is HasteUoy. Glass, glass-lined steel, or Teflon-lined piping and equipment are the preferred materials at elevated temperatures and/or high velocities or where trace Hon contamination is a problem, such as in the synthetic detergent industry. 

Grayness of a fabric swatch is not directly proportional to its content of black pigment (or artificial sod). A basic formula relating reflectance to the pigment content or concentration can be appHed to the evaluation of detergency test swatches (51,99—101). In simple form, an adaptation of the Kubelka-Munk equation, it states that the quantity (1 — i ) /2R (where R is the fraction of light reflected from the sample) is a linear function of the sod content of the sample. 

Lipases have proven to be effective in prespotters and other liquid detergent formulations when used in undiluted form for pretreatment of tough fatty stains. The low water content on the fabric in this situation is believed to be responsible for the high catalytic activity (50). 

Some potable supplies are treated surface waters from rivers, etc. These originally derive from any of the above, but will also contain the products of human activities, which lead to increased mineral contents and possibly some undesirable materials such as detergents. 

Carbon chain homolog distribution is nearly always the most important factor in determining performance and formulation characteristics of LAS [19]. Phenyl isomer distribution and dialkyltetralinsulfonate content have their greatest impact on the formulation characteristics of LAS in liquid detergents. 

ISO 4317 1991, Surface active agents and detergents Determination of water content—Karl Fischer method. 

The premise in this case is that the ether carboxylate and the noncoverted nonionic (also a detergent) as a whole are considered as active content. 

Reference 81 describes the use of a salt prepared from a trialkylamine or tris(hydroxyalkyl)amine and sulfonated C8-C20 a-olefins together with a sulfobetaine in a stable liquid detergent having a high content of dissolved electrolytes. These liquid detergents are useful for hair, hands, and clothing. 

The types of analyses discussed in this section can be divided into two groups active matter and impurities. Several methods assess the anionic surfactant (active matter) content of the AOS product. These are particularly important since detergent performance is directly related to surfactant concentration. The different types of anionic active material are identified and quantified. 

In mixtures of ester sulfonates and disalts the remission decreases as the content of disalts increases (Fig. 10). But small amounts of disalts do not have a strong negative effect on the detergency of the ct-sulfo fatty acid esters [581. 

When there is a limitation of the phosphorus content in detergents of 1%, then addition of phosphonates can act as an alternative solution in combination with other polyvalent ion-binding substances. Especially when magnesium is a cause of water hardness the zeoliths can form precipitations. But phosphonates, like hydroxyethanephosphonic acid (HEDP) and ethylenediaminetetra-methylenephosphonic acid (EDTMP), are able to sequester magnesium ions as well. 

As was pointed out, refinement of ethoxysulfated alcohols is sometimes required to satisfy current standards for product quality, in particular 1,4-di-oxane content. Due to the particular characteristics and outstanding suitability of FAES for application in personal care detergent products, the commercially accepted content of 1,4-dioxane in FAES has been progressively reduced to meet the demand of higher safety margins for the end-users, without requiring any change in product formulation and choice of surfactant. 

It may be noted that the ion exchange capacity is directly connected with the Al-content (each Al provides one negative charge). The zeolite used in detergent formulations (over 10 t/a) is NaA with Si/Al = 1, so with maximum exchange abi ity. 

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