The toxic metals in coal have different modes of occurrence required their frequent assessment by accurate and time-saving chemical fractionation schemes. In the current study, the conventional sequential extraction BCR (SE-BCR) method applied to recognize the chemical fraction of lead (Pb) in coal samples of recently developed Thar coalfield. The SE-BCR scheme modified with a time-saving single-step extraction (SSE) method assisted with ultrasound energy and conventional shaking devices under the same operating conditions applied for the original SE-BCR scheme. The conventional single-step extraction (CSS) and ultrasonic-assisted extractions (USE) methods efficiently reduced the time expected to separate all fractions by the SE-BCR method in 51 h to 22 and 2 h, respectively. The validity of both single-step extraction (SSE and USE) and SE-BCR methods were confirmed by applying certified reference material (CRM) of sediment (BCR-701) followed by the standard addition method. The Pb observed to be highest in the organic fraction (28.9-35.2%) and lowest in the acid-soluble fractions (1.39-2.61%) of coal samples at both blocks (X and XI) of Thar coalfield.

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