Designation: D2622 ? 16

Standard Test Method for

Sulfur in Petroleum Products by Wavelength Dispersive X-ray Fluorescence Spectrometry

波長色散x射線熒光光譜法測定石油產(chǎn)品中硫的標準試驗方法

1.Scope* 范圍

1.1 This test method covers the determination of total sulfur in petroleum and petroleum products that are single-phase and either liquid at ambient conditions, liquefiable with moderate heat, or soluble in hydrocarbon solvents. These materials can include diesel fuel, jet fuel, kerosene, other distillate oil, naphtha, residual oil, lubricating base oil, hydraulic oil, crude oil, unleaded gasoline, gasoline-ethanol blends, and biodiesel.

1.2 The range of this test method is between the PLOQ        value (calculated by procedures consistent with Practice D6259) of 3 mg/kg total sulfur and the highest level sample in the round robin, 4.6 weight % total sulfur.

N_OTE 1—Instrumentation covered by this test method can vary in sensitivity. The applicability of the test method at sulfur concentrations below 3 mg ?kg may be determined on an individual basis for WDXRF instruments capable of measuring lower levels, but precision in this test method does not apply.

1.2.1 The values of the limit of quantitation (LOQ) and    method precision for a specific laboratory’s instrument depends on instrument source power (low or high power), sample type, and the practices established by the laboratory to perform the method.

1.1 本試驗方法包括測定石油和石油產(chǎn)品中的總硫，這些石油和石油產(chǎn)品是單相的，在環(huán)境條件下是液態(tài)的，可在中等溫度下液化，或可溶于烴類溶劑。這些材料可以包括柴油、噴氣燃料、煤油、其他餾出油、石腦油、殘油、潤滑基礎(chǔ)油、液壓油、原油、無鉛汽油、汽油-乙醇混合物和生物柴油。

1.2 本試驗方法的范圍為3 mg/kg總硫的PLOQ值（按照與實施規(guī)程D6259一致的程序計算）與循環(huán)中的最高水平樣品4.6 %（重量）總硫之間。

注1：本試驗方法涵蓋的儀器靈敏度可能不同。對于能夠測量較低水平的WDXRF儀器，可單獨確定硫濃度低于3 mg/kg時試驗方法的適用性，但本試驗方法中的精度不適用。

1.2.1 特定實驗室儀器的定量限（LOQ）和方法精密度的值取決于儀器光源功率（低功率或高功率）、樣品類型和實驗室為執(zhí)行該方法而建立的實施規(guī)程。

14.Precision and Bias 精度和偏差

14.1 The precision of the test method was determined by statistical analysis of results obtained an interlaboratory study⁶ that included 27 samples including gasolines, distillates, biodiesel, residual oils, and crude oils. A pooled limit of quantitation (PLOQ) of approximately 3 mg/kg S was determined for all sample types. Precision for gasoline and diesel samples for high-power source XRF instruments is included in Appendix X1. The ranges of sulfur concentrations represented by the sample sets, together with the precisions, are listed in 14.1.1 and 14.1.2. These statistics apply only to samples having less than the level of interfering materials present shown in Table 1 (see also 1.4).

14.1.1 Repeatability—The difference between successive test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct   operation of the test method exceed the following values only in one case in twenty. Repeatability (r) may be calculated as shown in Eq 12 or Eq 13 for all materials covering the full       scope of this method. See Table 4 for calculated values.

14.1 通過對實驗室間研究⁶所得結(jié)果的統(tǒng)計分析，確定試驗方法的精密度，該研究包括27個樣品，包括汽油、餾分油、生物柴油、渣油和原油。對所有樣品類型確定了大約3 mg/kg S的合并定量限（PLOQ）。高功率光源X射線熒光儀器對汽油和柴油樣品的精密度包含在附錄X1中。14.1.1和14.1.2中列出了由樣品組表示的硫濃度范圍和精度。這些統(tǒng)計數(shù)據(jù)僅適用于小于表1所示干擾物質(zhì)水平的樣品（另見1.4）。

14.1.1 重復(fù)性--在長期運行中，在測試方法的正常和正確操作的情況下，由同一操作者在恒定操作條件下，對相同測試材料，使用同一儀器獲得的連續(xù)結(jié)果之間的差異，二十個中僅有一個超過以下值。對于涵蓋本方法全部范圍的所有材料，可以如公式12或公式13所示計算重復(fù)性(r)。計算值見表4。

Repeatability（r）= 0.1462·X^0.8015 mg/kg       (12)

Repeatability（r）= （0.1462·（（Y·10000）^0.8015））/10000 mass %       (13)

where:

X =   sulfur concentration in mg/kg total sulfur, and

Y =   sulfur concentration in mass % total  sulfur.

式中：

X = 總硫的硫濃度,以mg/kg為單位，以及

Y = 總硫的硫濃度，以質(zhì)量%為單位。

14.1.2 Reproducibility—The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would, in the long run, in the normal and correct operation of the test  method exceed the following values only in one case in twenty. Reproducibility (R) may be calculated as shown in Eq 14 or Eq 15 for all materials covering the full scope of this method. See Table 4 for calculated values.

14.1.2 再現(xiàn)性--在長期運行中，在測試方法的正常和正確操作的情況下，由不同實驗室的不同操作人員對相同測試材料獲得的兩個單獨和獨立結(jié)果之間的差異，二十個中僅有一個超過以下值。對于涵蓋本方法全部范圍的所有材料，可以如公式14或公式15所示計算再現(xiàn)性(R)。計算值見表4。

Repeatability（r）= 0.4273·X^0.8015 mg/kg       (14)

Repeatability（r）= （0.4273·（（Y·10000）^0.8015））/10000 mass %       (15)

where:

X =   sulfur concentration in mg/kg total sulfur, and

Y =   sulfur concentration in mass percent total  sulfur.

X = 總硫的硫濃度,以mg/kg為單位，以及

Y = 總硫的硫濃度，以質(zhì)量%為單位。

TABLE 4 Precision Values, All Sample Types

表4 精度值（所有樣品類型）

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