Table 2.

Sampling and analytical procedures of metals in soil matrix reported between different studies.

Order	Study area	No. of samples	Sample collection method			Method Instrument		Reference
			Period	Soil depth (cm)	Grid		Reference materials used
1	Albania	21	Jul ‘95	0–15	—	ICP-AES	CRMs-BCR 142R	[11]
2	Algeria	119	Jan-Feb ‘06	—	1 × 1 km	FAASa, GFSb	CRM 141 R, SRM 2709 SJS	[12]
3	Australia	25	Dec ‘00–Feb ‘01	0–5 and 5–20	—	ICP-MS	CRMs-AGAL 10, AGAL 11	[13]
4	Belgium	27	‘93–‘98	0–20	10 m interval	ICP-MS, ICP-AES	CRMs-SRM2710, GBW07411,	[14]
							GBW07311 & SRM1633
5	Bulgaria	14	Jun ‘04	—	—	XRF	—	[15]
6	Kosovo	82	Jun–Nov ‘02	—	1×1 km	XRF, ICP-MS	CRMs-BR, DR-N, GH, DTS-1,	[16]
							SDO-1, AGV-2, NIST 2709, 2710
7	Greece	30	‘93–‘94	—	—	INAAc & AAS	IAEA SOIL-7, Pepperbush SRM	[17]
8	Italy	280	—	0–5	—	ICP-MS	—	[18]
9	Jordan	3	Sept ‘03	0–20 and 20–40	—	AAS	—	[19]
10	Peru	6	—	0–10	—	ICP-ES	—	[20]
11	Slovenia	40	—	0–25	—	FAAS	WEPAL 2004.3.3	[21]
12	UK	70	—	0–15	1 km interval	FAAS	—	[22]
13	Bangladesh	53	Nov ‘95	0–5 and 5–15	—	AAS	—	[23]
14	India	30	‘02–‘04	—	—	XRF	SO-1, SO-2, SO-3, SO-4, NGRI-D,	[24]
							NGRI-U
15	Spain	24	Winter ‘07	0–5	—	ICP-MS & AAS-GF	CRM 052	[25]
16	Spain	27	Winter ‘05	0–3	—	ICP-MS	Lobster hepatopancreas	[26]
17	Turkey	29	Sep ‘03	—	—	FAAS	SRM - BCR-701	[27]
18	China	50	—	0–10	20 m × 20 m	XRF	GSS, GRS, GSD, SO-1, NIST-2709,	[28]
							NIST-2710, NIST-2711
20	Jordan	31	—	0–10 and 10–20	—	AAS	NBS SRMs	[29]
21	Pakistan	38	Oct ‘03–Dec ‘03	1–5	—	AAS	SRM-SR-96	[30]
22	Serbia	59	Jun ‘99–Mar ‘00	0–5	—	FAAS	—	[31]
23	Damascus	51	Summer ‘98	0–20	—	FAAS	—	[32]

^aFAAS—Flame atomic absorption spectrometer.

^bGFS—Graphite furnace spectrometry.

^cInstrumental Neutron Activation Analysis with gamma-ray spectroscopy.