Table 3.

Various analytical devices for determining adulterated drugs in herbal medicine.

Analyte	Matrix	Method	Media	LOD/LOQ	%RSD/ Recovery	Reference
Paracetamol	Herbal medicine powder	Optical sensor membrane	Polymer poly(methyl methacrylate) (PMMA)	Lowest measurable: 2.55–4.01 mg/mL	-	[22]
Allopurinol	Herbal medicine powder	A paper-based analytical device using colorimetry	Whatman filter paper No. 1, 4, 6 and Whatman 1 chromatography	Lowest measurable: 75 mg/mL	-	[13]
Dexamethasone and Prednisolone	Herbal medicine pellets	Electrochemical paper-based analytical device	Whatman SG81 paper	LOD dexamethasone: 3.59 µg/mL prednisolone: 11.988 µg/mL LOQ Dexamethasone: 6.00 µg/mL prednisolone: 20.02 µg/mL	Dexamethasone: 83 to 108% (recovery) and 5.6 to 10.1% (Coefficient of variation) prednisolone: 88 to 134% (recovery) and 4.4 to 13.8% (coefficient of variation)	[6]
Sibutramine	Powder (weight loss product)	A distance-based paper device with colorimetry	Filter paper	LOQ 0.22 mmol/L	Less than 4.4%RSD	[58]
Dexamethasone	Powder (joint-paint killer product)	Dipstick test using sensing film	Cellulose acetate film	LOD: 0.422 μg/mL LOQ: 1.406 μg/mL	Recovery: 99.978–101.144% RSD: <0.196%	[59]