Effects of Long-term Use of Raloxifene, a Selective Estrogen Receptor Modulator, on Thyroid Function Test

complex in a capillary, it is better to adjust the capillary so that the putty remains outside the ESR cavity: although the putty signals do not interfere with the Cu 2ϩ-DDC complex signals, they do change the baseline. Cu 2ϩ-DDC complex in 1-butanol is quite stable and is not affected by exposure to room light for a few hours. The peak height of the Cu 2ϩ-DDC complex remained unchanged for 3 days when the complex was kept in the dark, and the volume of 1-butanol was maintained. In the present method, Cu 2ϩ-DDC complex is placed in a hematocrit capillary first and the capillary is placed in the ESR cell; therefore, when a different sample is to be measured, only the capillaries are changed. This is very convenient because we do not need to wash the ESR cell between samples. The wall of the quartz capillary and the quartz wall of the ESR cell, however, have a weak signal at 3270 guass, as indicated by the arrow in Fig. 1A, part e, and may contain some substances that shift the baseline from a lower magnetic field to a higher magnetic field as observed in Fig. 1A. Therefore, the limit of detection is 15.7 nmol of copper (1 ng of copper). The signal of Fig. 1, part d, corresponds to 3 ng of copper. The sensitivity may improve when capillaries and ESR cells that do not have signals near the signal of copper become available. For the quantification of copper in plasma, flame AAS and color-imetry require 2 mL of plasma, but graphite furnace AAS and inductively coupled plasma-optical emission spec-trometry require 5 ␮L of plasma (11), which is the same amount as the present method. In ESR measurements, samples with higher concentrations can be measured without dilution, either by decreasing the gain from 10 4 to 1 or by decreasing the microwave power from 6 mW to nearly 0 mW. A small bench-top ESR instrument can be obtained at a cost comparable to that of an atomic absorption spectrometer. Sensitive, direct procedures for simultaneous determinations of iron and copper in serum, with use of