Designation: D7536 ? 16

Standard Test Method for

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

用單色波長色散X射線熒光光譜法測定芳烴中氯的標準試驗方法


1. Scope 范圍

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 該試驗方法包括在芳烴,其衍生物和相關化學品中通過單色,波長色散X射線熒光(MWDXRF)光譜法測定氯。

1.2 本試驗方法適用于氯濃度為0.66 mg / kg至10.07 mg / kg的樣品??梢酝ㄟ^用合適的溶劑定量稀釋樣品來確定更高的氯濃度。在一項實驗室間研究中,檢測限確定為0.18 mg / kg。



5. Significance and Use 意義和用途

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本試驗方法提供以最少的樣品制備和分析人員的參與,精確測量芳烴的氯含量。 每次分析的典型時間是五或十分鐘。

5.2 了解芳烴的氯含量對于過程控制以及預測和控制裝置腐蝕和催化劑中毒等操作問題,以及產品與商品規格的混合是非常重要的。

5.3 各種聯邦,州和地方機構管理一些石油產品的氯含量,包括芳香劑。 無偏和精確測定芳烴中的氯對于符合法規標準是至關重要的。



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 重復性 - 結果不應該是可疑的,除非它們的差異超過表1,表2或等式6所示。結果差異小于“r”的概率為95%是正確的。等式6顯示了兩次測量的平均值與“r”之間的關系。

r = 0.3 * X0.3 (6)

where:

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

式中:

X = 兩個平均氯濃度,單位為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 再現性 - 兩個實驗室提交的結果不應被視為可疑,除非它們的差異超過表1,表2或等式7所示。結果差異小于“R”的概率為95%是正確的。 公式7顯示了兩次測量的平均值與“R”之間的關系。

R = 0.5 * X0.5           (7)

where:

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

式中:

X = 兩個平均氯濃度,單位為mg / kg。

TABLE 2 Calculated Precision Values

表2 計算的精度值

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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