Khan et al. 2007 - metals in Withania somnifera from Pakistan

Khan, Ahmad, and Rahman measured chromium, lead, copper, cadmium, iron, nickel, and manganese in Withania somnifera plant parts collected from three locations in N.W.F.P./Peshawar Valley, Pakistan. The paper is occurrence evidence for botanical raw material used in traditional medicine, with paired soil measurements as collection-site context. The source reports total elemental metals by atomic absorption spectrophotometry; chromium is total Cr, not Cr-VI.

Key numbers

All values below are from Table 1 and are reported in mg/kg. The paper’s discussion prints mg/kg for the tabulated concentrations; no wet/dry conversion is applied here. nd means the paper reports “not detected.”

Paired soil rows are collection-site context and should not be pooled as botanical-product occurrence.

The discussion highlights the same table maxima in plant tissues, including Cr 0.10 mg/kg in Spot 1 leaves, Pb 0.46 mg/kg in Spot 1 stems, Cu 0.40 mg/kg in Spot 1 leaves, Cd 0.06 mg/kg in Spot 1 stems, Fe 19.74 mg/kg in Spot 1 leaves, Ni 0.17 mg/kg in Spot 1 leaves, and Mn 6.27 mg/kg in Spot 1 leaves.

Methods (brief)

The authors collected Withania somnifera from different locations of Peshawar Valley, authenticated the plant material at the PCSIR Labs herbarium, washed the samples with tap and distilled water, dried them at 60 °C, and milled the dried material through a 1.3 mm stainless-steel sieve. One-gram portions were dry-ashed for 24 hours at a temperature not exceeding 500 °C, treated with 20% HCl, filtered, diluted to 100 mL, and analyzed for Cr, Pb, Cu, Cd, Fe, Ni, and Mn using a Perkin Elmer atomic absorption spectrophotometer. The source reports total elemental metals; it does not report arsenic, mercury, or chromium speciation.

Implications

The paper contributes Pakistan occurrence data for herbal-botanical raw material, especially plant-part-specific Pb, Cd, Ni, and total Cr measurements in Withania somnifera. The paired soil values support a soil-to-plant collection-context note, but only the roots, stems, leaves, and fruits should be considered botanical occurrence rows.

Wiki pages this source may touch

• supplements-botanicals-herbs
• herbal-botanicals
• dried-herbs
• chromium
• lead
• copper
• cadmium
• iron
• nickel
• manganese

Verification notes

• Identity checks on 2026-06-09 found no existing source page for DOI 10.1002/jccs.200700049, raw handle MFK_khan2007, or cite key khan2007-withania-somnifera-metals-pakistan.
• DOI check: the DOI is not printed in /tmp/hmi-june9-100.txt; Crossref metadata for the exact title and journal reports DOI 10.1002/jccs.200700049.
• All Key numbers values were re-checked against Table 1 in /tmp/hmi-june9-100.txt extracted with pdftotext -layout. The table rows and nd cells are copied without averaging, rounding, or unit conversion.
• Units are preserved as mg/kg, the unit printed in the source discussion for the Table 1 values. The page does not convert to ppb.
• Speciation check: chromium is total Cr by AAS; the paper does not report Cr-VI. Arsenic and mercury are not measured in the occurrence table.
• Soil values are included only as paired collection-site context and should not be pooled as plant/product occurrence.
• Brand firewall check: no commercial brands or producers are reported.
• Closed vocabulary check: products, ingredients, metals, and wiki-page links use slugs present in docs/gpt-collaboration/taxonomy-snapshot.md. Species-specific Withania somnifera has no closed ingredient slug in the snapshot, so it remains in the title, prose, and matrix text only.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.