Table 3.

Method II: droplet deposition on large filter paper sheets

Sample matrix	Droplet volume	Size of dried residue	Sample loadinga	Surface material	LOD	Reproducibility	Additional information	Ref.
Blood spotted on paper, from a lab proficiency test	–	–	–	Whatmann filter paper	0.9 μg dL−1 (Pb)	7 % RSD (in-between droplets and also within droplet)	Sample directly spotted without any other treatment	[158]
Co in a drug preparation, Pb in whole blood, and Sn in food samples	500 nL	–	–	Filter paper with additive	1–60 ng L−1	10 % RSD (spot-to-spot)	Different additives to improve laser yield	[168]
Pb and Cd in BCR-634 whole blood reference material	200 pL	–	–	Filter paper with additive	0.5 pg Pb 0.02 pg Cd (equal to 2.5 and 0.1 ng L−1 with 200 nL of sample)	25 % for Pb and 8 % for Cd with standard solutions using 13C as internal standard, for samples: 5 % for Pb and 35 % for Cd	Repeated deposition of 65 pL droplets, ablation of several droplets at the same time	[167]
Blood (reference materials and real samples)	5 μL	5–6 mm	3 × 10−7 μL m−2	Filter paper	0.040–0.054 μg L−1	3–9 % RSD (quantitative) 1500 ppm (isotope ratios)	Analysis vial split aerosol-flow (single-collector/multi-collector ICP-MS)	[159]

^aSample volume/area of dried residue (assuming a circular spot)