Table 2.

Percent recovery of T4 in neat solutions after exposure to common labware surfaces.

A		Recovery of T4 after exposure to common lab items, mean percent recovered ± SD
Type of labware	Exposures	96-well 2 mL plates	n	14 mL clear glass tubes	n	Silanized clear 2 mL glass vials	n
Solvent A,	1	101 ± 2.5	5	98.7 ± 3.0	5	100 ± 7.8	5
100% Ethanol	5	98.3 ± 1.6	5	98.6 ± 2.5	4	94.5 ± 4.5	5
Solvent B,	1	100 ± 2.2	5	99.2 ± 3.3	5	99.9 ± 3.2	5
1.7% ammonium hydroxide in ethanol	5	101 ± 0.1	4	101 ± 2.4	5	97.0 ± 3.2	5
Solvent E,	1	98.2 ± 2.8	5	100 ± 1.0	5	98.3 ± 1.1	5
10% acetonitrile with 0.1% formic acid	5	93.7 ± 2.8	5	96.8 ± 2.9	5	89.9 ± 3.9	5

B	Mean percent difference between 1 and 5 exposures
	96-well 2 mL plates	p-value (α=0.05)	14 mL clear glass tubes	p-value (α=0.05)	Silanized clear 2 mL glass vials	p-value (α=0.05)
Solvent A	−2.8 ± 1.6	0.11	−0.1 ± 2.5	0.95	−5.3 ± 4.5	0.15
Solvent B	1.5 ± 0.1	0.21	2.1 ± 2.4	0.32	−2.9 ± 3.2	0.15
Solvent E	−4.6 ± 2.9	0.14	−3.2 ± 2.9	0.07	−8.6 ± 4.0	<0.05

Neat T4 solutions prepared in either solvent A (100% ethanol), solvent B (1.7% ammonium hydroxide in ethanol), or solvent E (10% v/v acetonitrile in water with 0.1% formic acid) were exposed to common labware (2 mL polypropylene 96-well plates, borosilicate glass 16 × 100 mm test tubes, or silanized clear 2 mL borosilicate autosampler vials) 1 and 5 times.

A). The percent of T4 recovered after exposure to labware was determined according to the formula 100*B/A, where B is the mean area ratio of samples spiked with internal standard post-exposure to labware, and A is the mean area ratio of the solutions spiked with internal standard pre-exposure.

B). The mean percent difference of recovery after 1 exposure to recovery after 5 exposures was evaluated for each labware and solvent using the paired t-test (α = 0.05).