Analysis of selected phthalates in Canadian indoor dust collected using household vacuum and standardized sampling techniques.

Phthalates have been used extensively as plasticizers to improve the flexibility of polymers, and they also have found many industrial applications. They are ubiquitous in the environment and have been detected in a variety of environmental and biological matrices. The goal of this study was to develop a method for the determination of 17 phthalate esters in house dust. This method involved sonication extraction, sample cleanup using solid phase extraction, and isotope dilution GC/MS/MS analysis. Method detection limits (MDLs) and recoveries ranged from 0.04 to 2.93 µg/g and from 84 to 117%, respectively. The method was applied to the analysis of phthalates in 38 paired household vacuum samples (HD) and fresh dust (FD) samples. HD and FD samples compared well for the majority of phthalates detected in house dust. Data obtained from 126 household dust samples confirmed the historical widespread use of bis(2-ethylhexyl) phthalate (DEHP), with a concentration range of 36 µg/g to 3840 µg/g. Dibutyl phthalate (DBP), benzyl butyl phthalate (BzBP), diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP) were also found in most samples at relatively high concentrations. Another important phthalate, diisobutyl phthalate (DIBP), was detected at a frequency of 98.4% with concentrations ranging from below its MDL of 0.51 µg/g to 69 µg/g.

Suppression of rat adjuvant arthritis by some acyclic nucleotide analogs.

The antiarthritic potential of two different acyclic nucleotide analogs, i.e. 9-(2-phosphonomethoxyethyl)adenine (PMEA), its bis(pivaloyloxymethyl)ester (Bis-POM-PMEA), and 1-(S)-(3-hydroxy-2-phosphonomethoxyethyl) cytosine (HPMPC) was investigated in the rat model of mycobacterial adjuvant-induced arthritis. With dependence on the dose, timing and route of administration, as well as on the genetic constitution of the arthritis-prone animals, PMEA was able to delay the onset, and substantially reduce or nearly completely inhibit the development of arthritic paw swelling. HPMPC was less active in this model. As compared with PMEA, its prodrug, Bis-POM-PMEA, expressed much more pronounced beneficial effects after both oral and i.p. administration.