Electrodialytic extraction of anionic pharmaceutical compounds from a single drop of whole blood using a supported liquid membrane.

A method to introduce target analytes to a chromatograph from a single drop of whole blood was investigated for minimally invasive monitoring of anionic pharmaceuticals. In this work, salicylate and loxoprofen were examined as organic anions. A micro ion extractor (MIE) has been developed for extraction of inorganic trace anions from whole blood, but this device is not suitable for extraction of pharmaceuticals. In the present study, we improved and optimized the MIE device for organic anion extraction. Various supported liquid membranes were evaluated for use as the ion transfer membrane, with each membrane placed between a droplet sample (donor) and an acceptor solution. A supported liquid membrane of porous polypropylene impregnated with 1-butanol was selected. In addition, the methods for electric field creation and electrode contact were examined to improve the characteristics of the MIE device. The current and extraction time were also optimized. With the optimized method, salicylate and loxoprofen were successfully extracted from a single drop of whole blood. Changes in the concentrations of these pharmaceuticals in blood over time were monitored after administration. As only 25µL of whole blood was required for analysis, repeat measurements could be conducted to monitor changes in the concentrations. This MIE will be useful for monitoring pharmaceutical concentrations in blood.

Micro Ion Extractor for Single Drop Whole Blood Analysis.

A micro ion extractor (MIE) was developed for trace anion determination by ion chromatography-mass spectrometry from a single drop (25 µL) of whole blood without pretreatment. Target analytes were iodide and thiocyanate, which play key roles in thyroid hormone production. Whole blood (25 µL) was pipetted from an earlobe or finger prick and placed in the 16 µL cavity of the device. A reproducible fraction of iodide and thiocyanate was transferred through a membrane to an acceptor solution layer by electromigration for 60 s. An isolator solution layer and a cation exchange membrane is provided between the acceptor and the anode to prevent gas formation or redox processes in the acceptor. The acceptor contents are transferred online to the ion chromatograph. Isolator solution composition and applied voltage were optimized. Recoveries from samples from 16 different volunteers of both sexes and differing ages were the same within ±10% relative standard deviation. Dietary effects on blood iodide and thiocyanate levels are reported. The very low sample requirement permitted multiple sample collections per day. The MIE device is expected to be useful for clinical studies that require several/many temporally spaced blood samples by keeping the invasive nature of blood collection as minimal as possible.

Levels, indoor-outdoor relationships and exposure risks of airborne particle-associated perchlorate and chlorate in two urban areas in Eastern Asia.

Indoor and outdoor concentrations of PM2.5-associated perchlorate (ClO4(-)) and chlorate (ClO3(-)) were investigated in Jinan, China, and size-resolved perchlorate and chlorate were studied in Kumamoto, Japan. The average outdoor PM2.5-associated concentrations of perchlorate and chlorate were 4.18 ng m(-3) and 2.82 ng m(-3), respectively, in Jinan. Perchlorate and chlorate were mainly distributed in fine particles, and their approximate PM2.5-associated concentrations were 0.04 ng m(-3) and 4.14 ng m(-3), respectively, in Kumamoto. The ratios of ClO3(-)/ClO4(-) ranged from 18.72 to 360.22 in Kumamoto and from 0.03 to 7.45 in Jinan. The highest concentration of perchlorate (173.76 ng m(-3)) was observed on Spring Festival Eve. This finding and the significant correlation between perchlorate and fireworks-related components (Cl(-) and K(+)) indicated that the fireworks display was a significant source of perchlorate in Jinan. The indoor concentrations of perchlorate and chlorate in Jinan were 3.54 ng m(-3) (range, 0.14-125.14 ng m(-3)) and 0.94 ng m(-3) (range, 0.10-1.80 ng m(-3)), respectively. In the absence of an indoor source of perchlorate, the occurrence of indoor concentrations higher than those found outdoors was a common effect of individual fireworks displays near the sampling sites, coupled with meteorological influences and poor indoor diffusion conditions. The exposure risks of perchlorate and chlorate indoors indicated that the potential risk of perchlorate exposure to children during fireworks displays is deserving of concern.