General Test Methods

Methods in this section are applicable to most anionic surfactants. Methods applicable only to specific compounds are presented in Section III. 

Active agent content of anionics is usually determined by titration with a cationic surfactant such as benzethonium chloride. Two-phase titration is suitable for assay of alkylaryl sulfonates alkyl sulfates and hydroxysulfates, alkanesulfonates, fatty alcohol ethoxysul-fates and alkyIphenolethoxysulfates and dialkyIsulfosuccinates (4,5). The results on ma- 

Marcel Dekker, Inc. 270 Madison Avenue, New York, New York 10016 

Equivalent weight of sulfated and sulfonated anionics can be determined directly by titration with base or by titration with a cationic surfactant. This requires that the active agent be isolated in relatively pure condition. A more general procedure is the para-toluidine hydrochloride method, which includes pimification of the anionic by extraction to eliminate interferences commonly found in detergents. These procedures are described in Chapter 16. 

While spectroscopic techniques will give a qualitative identification of the surfactant, detailed characterization of the hydrophobic portion of the molecule is almost always performed by gas chromatography. Because most anionic surfactants lack volatility, the compounds are desulfonated or derivatized before gas chromatographic analysis. Liquid chromatography is also suitable for the analysis. Although HPLC provides less information about isomers than does GC, it is usually possible to analyze the sample directly, without desulfonation or derivatization. These techniques are discussed in Chapters 7 and 8. 

---

The most important general test methods are issued as ASTM Test Methods and are periodically updated by the Polyurethane Raw Materials Analysis Committee (PURMAC) of the Society for the Plastics Industry (SPI). PURMAC has collected all pertinent analytical methods in a manual (271). 

Nutrients and diet supplements without claims of therapeutic effects are considered foods, and are thus regulated by the U.S. Food and Dmg Administration. These are further subject to specific food regulations. Specifications for pyridoxine hydrochloride (7) for foods are given in the Food Chemicals Codex (80) and for pharmaceuticals in the US. Pharmacopeia (81). General test methods have been summarized (82). 

The sulfated ash in oxytetracycline is determined using the general test method ... 

In January 1981, EPA published a Premanufacture Testing Policy containing general test methods and guidelines for a large number of human and environmental effects. A6 Fed. 

ISO 75-1 2004 Plastics - Determination of temperature of deflection under load - Part 1 General test method... 

ASTM 1980 Annual Book of Standards, Parts 35-38. Pipe and Building Products, General Test Methods, Part 36, Film, reinforced and cellular plastics, high modular fiber and composites Part 37, 38, published by American Society for Testing Materials, Philadelphia, Pennsylvania. 

A number of international standards have been published which give specific test mix recipes and evaluation procedures for particular polymers. These are recorded in references 2-11 and similar British and ASTM methods also exist. These standards refer to the general test methods and standard methods of preparation which are discussed below but include additional detail relevant to the polymer in question. They also include very limited testing on the vulcanisates. The main purpose of these standards is to provide a basis for comparison and evaluation of particular polymers as regards their processing and vulcanisation characteristics their scope does not extend to the general physical properties of vulcanisates. 

Siaff Rubber, Natural and Synthetic-General Test Methods, Carbon Black. American... 

To date, in its action plan for harmonization, the PBG has placed a high priority on the monographs of major excipients that can be used for a number of new drug products as well as on important general test methods. The PBG has established its general policy for harmonization, in which it is shown that the goal of harmonization is to bring the policies, standards. 

MIL-STD-401B Sandwich Constructions and Core Materials General Test Methods, 26 September 1967, 35 pp (FSC 5680) (AS)... 

Loss on ignition Following die general test method <733>, the material is ignited to 1000°C to constant weight. The material can not lose more than 6.5% of its own weight. 

ASTM Standards Book, 09.01 Rubber, Natural and Synthetic — General Test Methods Carbon Black, ASTM, West Conshohocken, PA, USA, 2008. 

Generally, test methods that should be observed are prescribed in standards such as ASTM D6751 or EN14214. However, in many cases, other test methods, usually developed by professional organizations, may be simpler, less expensive, and more suitable for process development. For example, since biodiesel is an oleochemical product, test methods developed by organizations, such as the American Oil Chemists Society (AOCS), are often well-suited, while ASTM methods were often developed specifically for petrodiesel. 

Loss on drying The general test method <731 > is followed. After being dried at 105°C for 3 hours, the material cannot lose more than 0.5% of its weight. 

BS 2782. Method 121. General test method for determination of temperature of deflection under load of plastics, 1994. 

The flammability of plastics in packaging has to be evaluated using the general test methods for plastics. 

Several methods of determination can be used, but two, distillation and gas chromatography are the most popular. Industrial aromatic hydrocarbons are determined by distillation. The temperature is recorded for the initial boiling point, for the sample which has been distilled at 5%, 10%, then at 10% increments up to 90 /o, then finally at 95%. The temperature should be recorded with precision of 0. TC. A general test method to determine the distillation range of volatile liquids outlines a similar method of measurement. In addition to the measurements at the intervals given above, the temperature of the dry point (distillation temperature of residual quantities) is also recorded. Results must be reported as specified in the method. 

Plastics—Determination of Water Absorption Plastics—Determination of Temperature of Deflection under Load—Part 1 General Test Method... 

Paint and Varnishes, Vol. I General Test Methods, Vol. 2 Raw Materials (ISO Standards Handbooks, 1994). 

Some detailed examples of ASTM protocols for the characterization of UO2 are presented later in order to demonstrate the procedures. Determination of uranium, oxygen, and the 0 U atomic ratio by the ignition (gravimetric) impnrity correction method is part of the general test methods for UO2 (C696 2011). The sample (5-10 g of powdered... 

S Standards, Rubber, Natural and Synthetic—General Test Methods, and Materi-alscos Part QQ Q1, American Society for Testing and Materials, Philadelphia, Pa. 

DIN EN ISO 75-1, Plastics - Determination of Temperature of Deflection Under Load - Part 1 General Test Method, 2005. 

---