Table 1.

Study characteristics, methods of skin volatile organic compound (VOC) sampling, and analytical platform used.

	Sampling Location	Patient Cohort	Number of Participants	Analytical Instrument	Method of Skin VOC Collection	Sorbent Material	Sampling Time (Hours)	Skin Cleaning Prior to Testing	Sample Storage Temperature		Sample Storage Time	Number of Significant Skin Compounds	Reference
Monedeiro 2020	Lower back	Visceral adenocarcinoma	64	GC–MS	SPME direct contact	Cotton pad	48	Sampling location cleaned with isopropanol	−20		Immediate processing	72	[18]
Ashrafi 2020	Upper arm	Healthy	5	GG–MS	Direct wound headspace onto TD tubes and PDMS direct contact patches	Custom 3D polylactic funnels to create headspace over the wound for headspace, PDMS patches	0.5	No use of exogenous products for 24 h before sampling	n/a		Within 24 h	10	[19]
Vishinkin 2021	Inner arm and chest	Active TB infection	461	GC–MS	Static headspace no concentration step	PDMS patch, porous polymeric pouches containing poly (2,6-diphenyl phenylene oxide)	1	No smoking for 30 min before	4		Up to 8 months	6	[20]
Roodt 2018	Ankle, wrist	Healthy	2	2D GC ToF MS	PDMS bracelet directly into GC	PDMS bracelets	4	No effort to control environmental factors	−80		Max 72 h	87	[21]
Wooding 2020	Ankle, wrist	Healthy	20	GCxGC-ToF-MS	PDMS sampler directly analysed in GC	PDMS patch	1	Medical-grade alcohol cleansing pads (70% isopropanol) used to clean the skin surface	4		Within 48 h	39	[11]
Grabowska-Polanoska 2017	Forearm	Healthy	8	GC–MS	(a) Forearm headspace using Cellulose bag (60x 30 cm)	(b) Cellulose sachets filled with active carbon (patch)	Carbotrap X	2	Y (refrain from perfume, deodorants, fragrance-free soaps)	n/a	Immediate processing	49	[22]
Duffy 2017	Forearm	Mechanical barrier disruption	7	GC–MS	Static headspace SPME		50/30 ym DVB/Carboxen/PDMS SPME, held in glass vial	0.25	Y (no cosmetics on the area on the day, wash with olive-based soap)	n/a	Immediate processing	37	[23]
Mochalski 2014	Hand, forearm	Healthy	31	GC–MS	SPME static headspace		Nalophan bags, 75 ym Carboxen/PDMS	0.5	Wash arm with tap water and dry with a paper towel	immediate processing	Immediate processing	22	[24]
Prada 2011	Hand	Healthy	6	GC–MS	Headspace SPME (DVB/CARB on PDMS) and direct sampling with contact SPME		Cotton, rayon, polyester, wool	12	no	n/a	Immediate processing	58 (direct sampling) and 20 (headspace)	[25]
Dolezal 2017	Hand	Healthy	9	2D GC ToF MS	Solvent extraction from glass beads		40 glass beads (4.86 mm), hexane for solvent	0.2	Y (wash hands with non-perfume soap)	Below 7	Unknown	137	[26]
Bernier 2000	Hand	Healthy	4	GC–MS	TD of glass beads into GC port		2.9 mm glass beads	0.25	No specific instructions prior to collection but hand washing with the same soap on arrival	n/a	Immediate processing	233	[27]
Kusano 2013	Hand	Healthy	31	GC–MS	Headspace SPME		Gauze pads in a glass vial, 50/30 ym DVB/Carboxen on PDMS	0.2	Hand washing pre-collection with olive-based soap	n/a	Immediate processing	217	[28]
Broza 2014	Hand	Healthy	30	GC–MS	Direct dynamic headspace to TD tube		Direct headspace of VOCs onto to Tenax/Carboxen TD tube using a pump	Immediate	Washed with water for 1 min	Up to 1 week	Up to 1 week	12	[29]
Curran 2007	Hand	Healthy	60	GC–MS	Headspace SPME		Headspace SPME of pre-treated gauze, SPME (CAR/DVB/PDMS 50/30 ym)	0.17	Hand washing 30 s olive-based soap, washing with water, air drying	21	Immediate processing	62	[30]
Zhuo-Min 2005	Hand/forearm	Healthy	15	GC–MS	Static Headspace SPME		Hand-placed in stainless steel jar/glass jar, SPME 65 ym DVB/PDMS	0.5	no	n/a	Immediate processing	34	[31]
Turner 2008	Hand/forearm	Healthy	5	SIFT MS	Dynamic headspace		Nalophan bags	0.12	No	n/a	Immediate processing	6	[32]
Gallagher 2008	Forearm, back	Healthy	25	GC–MS	SPME static headspace using 50/30 ym DVB/Carboxen on PDMS		Direct headspace using a glass funnel	0.5	No	−12 (only for solvent)	Immediate processing	56	[6]
					Solvent extraction		Double distilled ethanol			n/a		49
Martin 2016	Forehead	Healthy	15	GC–MS	PDMS patch		PDMS	0.5	No	−80	Stored until processing	30	[33]
Verhulst 2016	Axilla, hands, feet	Healthy	8	GC–MS	Static headspace of cotton pads onto TD unit		Cotton pads	0.13	No	−80	Max 21 days	4	[34]
Dormont 2013	Feet	Healthy	26	GC–MS	Solvent extraction		Diethyl ether/dichloromethane	0.03	Washed sampling area with water	n/a	Immediate processing	32	[35]
					SPME static headspace		50/30 ym DVB/Carboxen on PDMS on StableFlex fibres	0.75		n/a		23
					SPME patch (direct contact)		50/30 ym PDMS-DVB/CAR	0.05		n/a		24
					Dynamic headspace		Nalophan bags, Carbotrap, Tenax	0.33		n/a		38
Ruzsanyi 2012	Navel	Healthy	7	GC–IMS	Real-time VOC collection by IMS		102 mm stainless steel pan	0.08	Avoid alcohol 12 h, no cosmetics on day	n/a	Immediate processing	10	[36]
Thomas 2010	Lower limb	Chronic arterial leg wounds	5	GC–MS	PDMS skin patches		Direct patch, inserted into TD tubes	0.5	Washed with distilled water 24 H before sampling	n/a	Unknown	46	[37]
Haze 2001	Upper back	Healthy	22	GC–MS	Dynamic headspace of T shirt		Tedlar bags, Tenax	72	Y odourless soaps/cosmetics	n/a	Immediate processing	22	[38]
Curran 2005	Axilla	Healthy	4	GC–MS	Static Headspace SPME		Sterile gauze, SPME DVB/Carboxen on PDMS	24	Olive oil soap for 48 h during shower	21	Immediate processing	46	[8]
Meijerink 2000	Forehead sweat	Healthy	14	GC–MS	Dynamic headspace		Tenax pooled sweat	3	Avoid soap/cosmetics for 24 h	n/a	Immediate processing	76	[39]
Mochalski 2014	Whole body	Healthy	10	SRI-ToF-MS	Body plethysmography chamber		Headspace directly loaded onto MS	1	Asked to fast for 12 h prior and refrain from using cosmetics	Immediate processing	Immediate processing	64	[24]
Mochalski 2018	Whole body	Healthy	11	GC–IMS	Headspace		Whole body plethysmography chamber (bodyscope)	1	Y (refrain from cosmetics for 12 h)	n/a	Immediate processing	17	[40]
Abaffy 2013	Melanoma biopsy samples	Melanoma	10	GC–MS	PDMS/DVB SPME headspace of biopsy		Biopsy put into headspace vials with SPME as a concentration step	1	No	n/a	Immediate processing	6	[41]
Abaffy 2010	Melanoma biopsy samples in headspace vials	Melanoma vs. benign nevi	20	GC–MS	SPME		PDMS-DVB	1	No	n/a	Immediate processing	9	[42]