Paper spray high-resolution accurate mass spectrometry for quantitation of voriconazole in equine tears

An eye on the dog as the scientist's best friend for translational research in ophthalmology: Focus on the ocular surface

“…With sponges, however, the operator can only control the duration of tear collection and not the volume of tears soaked up in each individual. The resulting variability in tear volume absorbed often translates into large intra‐ and inter‐subject variability in the concentration of the compound(s) of interest, as shown for protein content 209 and various drugs such as doxycycline, 214 minocycline, 271 voriconazole, 272 and ofloxacin 244 . On the other hand, the ability to control the volume of tears absorbed with Schirmer strips (i.e., same mm mark) generally improves the reproducibility of the results 209,214,215,273 …”

“…Further, the standard calibration curve solutions should be constructed by spiking known drug concentrations and internal standard onto Schirmer strips, followed by the same extraction protocol as for biological samples; this step is equivalent to “spike and recover” experiments recommended for other analytes such as cytokines 265 and proteins 257 . Last, actual tear fluid should be used whenever possible as the selected matrix for standard calibration curve and quality control solutions, 214,215,272 as the reported surrogates (e.g., artificial tear solution) 279 do not account for chemical interferences and matrix effects that typically occur with a complex biological fluid (e.g., ionization suppression) 272 . Blank tears can be collected with absorbent materials before study initiation, retrieving up to 84 µl in 1 min with ophthalmic sponges in dogs 264 and 132 µl in 12 min with successive substitutions of polyurethane mini‐sponges in humans 236 …”

Assessment of greenness for the determination of voriconazole in reported analytical methods

“…Recently, Lerch et al 132 developed a rapid and efficient analytical technique called paper spray mass spectrometry (PSMS), used for the first time to quantify VOR in the complex biological matrix without using chromatographic or traditional sample separation. An innovative PSMS technique for quantitating VOR in equine tears has been determined and corroborated over a series of 10 to 1000 ng mL −1 .…”

An Eye on the Dog as the Scientist’s Best Friend for Translational Research in Ophthalmology: Focus on the Ocular Surface

“…221 With sponges, however, the operator can only control the duration of tear collection and not the volume of tears soaked up in each individual. The resulting variability in tear volume absorbed often translates into large intra-and inter-subject variability in the concentration of the compound(s) of interest, as shown for protein content 143 and various drugs such as doxycycline, 159 minocycline, 222 voriconazole, 223 and ofloxacin. 191 On the other hand, the ability to control the volume of tears absorbed with Schirmer strips (ie., same mm mark) generally improves the reproducibility of the results.…”

“…Second, the standard calibration curve solutions should be constructed by spiking known drug concentrations and internal standard onto Schirmer strips, followed by the same extraction protocol as for biological samples; this step is equivalent to 'spike and recover' experiments recommended for other analytes such as cytokines 216 and proteins. 207 Third, actual tear fluid should be used whenever possible as the selected matrix for standard calibration curve and quality control solutions, 159,160,223 as the reported surrogates (eg., artificial tear solution) 230 do not account for chemical interferences and matrix effects that typically occur with a complex biological fluid (eg., ionization suppression). 223 Blank tears can be collected with absorbent materials prior to study initiation, retrieving up to 84 µL in 1 min with ophthalmic sponges in dogs 214 and 132 µL in 12 min with successive substitutions of polyurethane mini-sponges in humans.…”