定价： 78元 / 折扣价： 67 元 加购物车

定价： 78元 / 折扣价： 67 元 加购物车

定价： 78元 / 折扣价： 67 元 加购物车

Low operating temperature fuel cells such as proton exchange membrane (PEM) fuel cells require high purity hydrogen for maximum material performance and lifetime. Analysis to part-per-billion (ppb) concentration of individual cation contaminants such as potassium, sodium and ammonium in hydrogen and related fuel cell supply gases is necessary for assuring a feed gas of sufficient purity to satisfy fuel cell system needs. More specifically, cations such as ammonium causes irreversible performance degradation of proton exchange membranes used in low temperature fuel cells by reacting with protons in the membrane to form ammonium ions.Although not intended for application to gases other than hydrogen and related fuel cell supply gases, techniques within this test method can be applied to other gaseous samples requiring cation analysis.1.1 This test method describes a procedure for the determination of cations in hydrogen and other fuel cell feed gases. It has been successfully applied to other types of gaseous samples including air, engine exhaust, and landfill samples. An ion chromatograph/conductivity detector (IC/CD) system is used to determine cations. Sensitivity from low part per billion (ppb, μg/l, μg/kg) up to part per million (ppm, mg/l, mg/kg) concentration are achievable dependant on the amount of hydrogen or other fuel cell gas sampled. This test method can be applied to other gaseous samples requiring analysis of trace constituents provided an assessment of potential interferences has been accomplished.1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元

4.1 The procedure described is for the quality control for manufacturing liquors and specifications for the purchase of such liquors.4.2 The chromium content of the liquors determines the amount to be used to obtain the desired degree of tannage, and hence may be a matter for specification in the purchase of leather.1.1 This test method covers the determination of chromic oxide in chrome tanning liquors, either simple, with added aluminum or zirconium, or with the usual masking complexing agents.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 This test method is used to determine the percent actives in each type of the disinfectant quaternary ammonium salts, and also in the disinfectant products. Quaternary ammonium compounds being the active ingredients in disinfectant-type products require accurate determination to assess the cost and antimicrobial performance of such products. 1.1 This test method covers a potentiometric titration procedure for determining active matter in disinfectant quaternary ammonium salts. This test method is intended for the analysis of quaternary ammonium salts used as disinfectants, and only applies to the following commonly used quaternary ammonium salts: n-alkyldimethylbenzylammonium chloride (see Fig. 1), cetyltrimethylammonium chloride, and a blend of n-octyldecyl dimethylammonium chloride, di-n-octyl dimethylammonium chloride, and di-n-decyldimethyl ammonium chloride (see Fig. 2). Also, this test method can be applied to the analysis of disinfectant type products where the formula ingredients are known and the quaternary ammonium salt is one of the above. Interferences such as amines oxides and betaines present in disinfectant formulations were not tested. X−   =   chloride, and R   =   aliphatic, normal C8 − C22.

定价： 515元 / 折扣价： 438 元 加购物车

4.1 This test method is used to determine the quaternary ammonium salts commonly found in fabric softeners. Quaternary ammonium compounds being the active ingredients in fabric softeners requires accurate determination to assess the cost and performance of such compounds.1.1 This test method describes a potentiometric titration procedure for the determination of quaternary ammonium salts in fabric softeners. This test method is intended for the analysis of known quaternary ammonium salts such as the dialkyl dimethyl quaternary ammonium compound type and the diamidoamine based quaternary ammonium compound type.1.2 The quaternary ammonium salts conform to the structures shown in Fig. 1 and Fig. 2.1.3 The analytical procedure appears in the following order:  SectionApparatus  5Reagents  6Preparation of standard reagents  7Standardization of hyamine solution  9Safety precautions  8Procedure for determination of dialkyl dimethyl quaternaries 10Procedure for determination of diamidoamine based quaternaries 111.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. See 6.4, 6.6, 6.7 and Section 8 for specific warning statements.

定价： 0元 / 折扣价： 0 元

2.1 This test method is intended for use in the determination of the acidity as free fatty acids in the absence of ammonium or triethanolamine soaps in sulfonated and sulfated oils for the purpose of quality assurance.1.1 This test method covers the determination of the acidity as free fatty acids existing in a sample of sulfonated or sulfated oil, or both, by titrating the sample dissolved in a solvent. It is not applicable in the presence of ammonium or triethanolamine soaps or salts or other compounds that do not react neutral to phenolphthalein when dissolved in alcohol.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

3.1 This test method is intended for use in the determination of the acid number of sulfonated and sulfated oils for the purpose of quality assurance.1.1 This test method covers determination of the acidity as free fatty acids in the presence of ammonium or triethanolamine soaps, or both, existing in a sample of sulfonated or sulfated oil, or both, by calculation from the total alkalinity and free-and-alkali combined fatty acids.1.2 The values stated in SI units are to be regarded as standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 Exposure to beryllium can cause a potentially fatal disease, and occupational exposure limits for beryllium in air and on surfaces have been established to reduce exposure risks to potentially affected workers (1, 2).5 Measurement of beryllium in matrices such as soil and sediment is important in environmental remediation projects involving beryllium contamination (3) and for establishment of background levels of beryllium at sites where anthropogenic beryllium may have been used (2, 4-6). Sampling and analytical methods for beryllium are needed in order to meet the challenges relating to exposure assessment and risk reduction. Sampling and analysis methods, such as the procedure described in this test method, are desired in order to facilitate measurements of beryllium that can be used as a basis for management of remediation projects and protection of human health.5.2 This test method can be used for purposes such as environmental remediation projects where beryllium is a contaminant of concern. It is also useful for characterization of levels of beryllium in soil at sites where beryllium is in mining or manufacturing applications, and for determination of background levels of beryllium in soil.5.3 The limit of quantification of this test method varies with the dilution factor (see 13.6.1). For the detection solution containing lysine the detection limit is 0.013 mg beryllium per kilogram of sample, based on a 0.5 g sample (7) extracted in a 50 mL extraction solution and analyzed using a dilution factor of 20×. When the lysine-free detection solution is used one may use a 20× dilution factor and obtain the same detection limit or use 5× dilution factor and obtain a detection limit of 0.004 mg/kg of sample.NOTE 1: Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.1.1 This test method is intended for use in the determination of beryllium in samples of soil and sediment. This test method can be used for purposes such as environmental remediation projects where beryllium is a contaminant of concern. It is also useful for characterization of levels of beryllium in soil at sites where beryllium is in mining or manufacturing applications, and for determination of background levels of beryllium in soil.1.2 This test method assumes that samples of soil or sediment are collected using appropriate and applicable methods.1.3 This test method includes a procedure for extraction (dissolution) of beryllium in dilute ammonium bifluoride, followed by analysis of aliquots of the extract solution using a beryllium-specific fluorescent dye.1.4 For a 500 mg sample, the lower limit of the working range is approximately 0.04 mg Be/kg (5× dilution) or 0.1 mg Be/kg (20× dilution). The working range extends to concentrations of at least 500 mg Be/kg.1.5 No detailed operating instructions are provided because of differences among various makes and models of suitable fluorometric instruments. Instead, the analyst shall follow the instructions provided by the manufacturer of the particular instrument. This test method does not address comparative accuracy of different devices or the precision between instruments of the same make and model.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.7 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.7.1 For purposes of comparing a measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal of significant digits in the specified limit.1.7.2 The procedures used to specify how data are collected/recorded, or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering data.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This test method is applicable to the simultaneous determination of dissolved alkali and alkaline earth cations and ammonium in water and wastewaters. Alkali and alkaline earth cations are traditionally determined by using spectroscopic techniques, such as AAS or ICP; whereas ammonium can be measured by using a variety of wet chemical methods, including colorimetry, ammonia-selective electrode, and titrimetry. However, ion chromatography provides a relatively straightforward method for the simultaneous determination of cations, such as lithium, sodium, potassium, calcium, magnesium, and ammonium, in fewer than 20–30 min.1.1 This test method is valid for the simultaneous determination of the inorganic alkali and alkaline earth cations, lithium, sodium, potassium, magnesium, and calcium, as well as the ammonium cation in reagent water, drinking water, and wastewaters by suppressed and nonsuppressed ion chromatography.1.2 The anticipated range of the test method is 0.05–200 mg/L. The specific concentration ranges tested for this test method for each cation were as follows (measured in mg/L):Lithium 0.4–10.0Sodium 4.0–40.0Ammonium 0.4–10.0Potassium 1.2–20.0Magnesium 2.4–20.0Calcium 4.0–40.01.2.1 The upper limits may be extended by appropriate dilution or by the use of a smaller injection volume. In some cases, using a larger injection loop may extend the lower limits. It is the responsibility of the user to ensure the validity of this test method for concentrations if the range is extended.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 It is the user’s responsibility to ensure the validity of these test methods for waters of untested matrices.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For hazards statements specific to this test method, see 8.3.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This practice is intended for the digestion of metals and metalloids in airborne dust and dust wipe samples collected during various activities performed in and around workplaces, buildings and related structures.5.2 This practice is applicable to the digestion of airborne dust and dust wipe samples collected in accordance with Test Method D4532, Guide D6062, Practice D7144 or Guide E1370 for airborne dust, and Practices D6966, D7296, D7822, or E1728 using wipes that may or may not conform to Specifications D7707 or E1792.5.2.1 This practice is applicable to the digestion of airborne dust sample filters that have been removed from their sampling cassettes which have been wiped to collect all dust adhering to the side walls and included in the hard-walled containers as part of the collected samples.5.2.2 This practice is applicable to the digestion of airborne dust samples that use acid-soluble cellulosic air sampling capsules with the entire contents of the cassettes transferred to hard-walled containers.5.2.3 This practice is applicable to the digestion of settled dust samples collected using wipe materials in hard-walled containers.5.3 Digestates prepared according to this practice are intended to be analyzed for metal and metalloid concentrations using spectrometric techniques such as inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry (ICP-OES), graphite furnace atomic absorption spectrometry (GFAAS), and flame atomic absorption spectrometry (FAAS) (see Test Methods D4185, D6785, D7035, D7439, E1613, E3193, and E3203), or for lead using electrochemical techniques such as anodic stripping voltammetry (see Practice E2051), or for beryllium using optical fluorescence detection (see Test Method D7202).5.4 Laboratories developing in-house test methods using this procedure shall determine precision and bias in accordance with the principles laid down by their accrediting agency.1.1 This practice covers the digestion of airborne and surface dust samples (collected using air and wipe sampling practices) and associated quality control (QC) samples for the determination of metals and metalloids by means of a mixture of dilute ammonium bifluoride and nitric acid.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This practice contains notes which are explanatory and not part of mandatory requirements of the standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 There is a need to monitor the content of metals and metalloids in order to determine the presence of potential hazards. Hence, effective and efficient methods are required for the preparation of soil samples for determination of metals and metalloids present therein.5.2 This practice may be used for the digestion of soil samples that are collected during various construction and renovation and hazard survey activities in and around buildings and related structures. The practice is also suitable for the digestion of soil samples for metal and metalloid analyses collected from other locations, such as near roads and steel structures. For some other extraction procedures, see Practices D3974.5.3 This practice is intended to be used to prepare samples that have been collected for hazard assessment purposes but may be used for other applications such as, for example, monitoring the effectiveness of remediation activities.5.4 This practice may be capable of determining metals and metalloids bound within matrices, such as silica, that are not soluble in nitric acid alone.5.5 This practice includes drying and homogenization steps to help assure that reported results are representative of the sample and are independent of potential differences in soil moisture levels among different sampling locations or changing weather conditions.1.1 This practice covers drying, homogenization, and ammonium bifluoride-nitric acid digestion of soil samples and associated quality control (QC) samples for the determination of metals and metalloids using laboratory atomic spectrometry analysis techniques such as inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectrometry (ICP-AES), flame atomic absorption spectrometry (FAAS), and graphite furnace atomic absorption spectrometry (GFAAS). For ammonium bifluoride-nitric acid digestion of airborne dust and dust-wipe samples for the determination of metals and metalloids, see Practice D8344.1.2 This practice is based on U.S. EPA SW 846, Test Method 3050, Test Method D7202, and Practice D8344.1.3 This practice contains notes that are explanatory and are not part of the mandatory requirements of this standard.1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车