Designation: D7536 - 16

Standard Test Method for

Chlorine in Aromatics by Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry

用单色波长色散X射线荧光光谱法测定芳烃中氯的标准试验方法


1. Scope 范围

1.1 This test method covers the determination of chlorine by monochromatic, wavelength-dispersive X-ray fluorescence (MWDXRF) spectrometry in aromatic hydrocarbons, their derivatives, and related chemicals.

1.2 This test method is applicable to samples with chlorine concentrations from 0.66 mg/kg to 10.07 mg/kg. Higher chlorine concentrations can be determined by quantitatively diluting the sample with a suitable solvent. In an interlaboratory study, the limit of detection was determined to be 0.18 mg/kg.

1.1 该试验方法包括在芳烃,其衍生物和相关化学品中通过单色,波长色散X射线荧光(MWDXRF)光谱法测定氯。

1.2 本试验方法适用于氯浓度为0.66 mg / kg至10.07 mg / kg的样品。可以通过用合适的溶剂定量稀释样品来确定更高的氯浓度。在一项实验室间研究中,检测限确定为0.18 mg / kg。



5. Significance and Use 意义和用途

5.1 This test method provides for the precise measurement of the chlorine content of aromatics with minimal sample preparation and analyst involvement. The typical time for each analysis is five or ten minutes.

5.2 Knowledge of the chlorine content of aromatics is important for process control as well as the prediction and control of operational problems such as unit corrosion and catalyst poisoning, and in the blending of products to commodity specifications.

5.3 Various federal, state, and local agencies regulate the chlorine content of some petroleum products, including aromatics. Unbiased and precise determination of chlorine in aromatics is critical to compliance with regulatory standards.

5.1本试验方法提供以最少的样品制备和分析人员的参与,精确测量芳烃的氯含量。 每次分析的典型时间是五或十分钟。

5.2 了解芳烃的氯含量对于过程控制以及预测和控制装置腐蚀和催化剂中毒等操作问题,以及产品与商品规格的混合是非常重要的。

5.3 各种联邦,州和地方机构管理一些石油产品的氯含量,包括芳香剂。 无偏和精确测定芳烃中的氯对于符合法规标准是至关重要的。



16. Precision and Bias 精度和偏差

16.2 Repeatability—Results should not be suspect unless they differ by more than shown in Table 1, Table 2, or Eq 6. Results differing by less than “r” have a 95 % probability of being correct. Eq 6 shows the relationship between the average of two measurements and “r.”

16.2 重复性 - 结果不应该是可疑的,除非它们的差异超过表1,表2或等式6所示。结果差异小于“r”的概率为95%是正确的。等式6显示了两次测量的平均值与“r”之间的关系。

r = 0.3 * X0.3 (6)

where:

X = the average chlorine concentration of two results in mg/kg.

式中:

X = 两个平均氯浓度,单位为mg / kg。

16.3 Reproducibility—Results submitted by two labs should not be considered suspect unless they differ by more than shown in Table 1, Table 2, or Eq 7. Results differing by less than “R” have a 95 % probability of being correct. Eq 7 shows the relationship between the average of two measurements and “R.”

16.3 再现性 - 两个实验室提交的结果不应被视为可疑,除非它们的差异超过表1,表2或等式7所示。结果差异小于“R”的概率为95%是正确的。 公式7显示了两次测量的平均值与“R”之间的关系。

R = 0.5 * X0.5           (7)

where:

X = the average chlorine concentration of two results in mg/kg.

式中:

X = 两个平均氯浓度,单位为mg / kg。

TABLE 2 Calculated Precision Values

表2 计算的精度值

Cl,

Concentration,

mg/kg

Repeatability r,

mg/kg

Eq 6 values

Reproducibility R,

mg/kg

Eq 7 values

0.66

0.26

0.41

0.75

0.28

0.43

1.00

0.30

0.50

2.00

0.37

0.71

5.00

0.49

1.12

7.00

0.54

1.32

10.07

0.60

1.59




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