A high-efficiency real-time digital signal averager for time-of-flight mass spectrometry.

Rationale: Analog-to-digital converter (ADC)-based acquisition systems are widely applied in time-of-flight mass spectrometers (TOFMS) due to their ability to record the signal intensity of all ions within the same pulse. However, the acquisition system raises the requirement for data throughput, along with increasing the conversion rate and resolution of the ADC. It is therefore of considerable interest to develop a high-performance real-time acquisition system, which can relieve the limitation of data throughput.

[CAIS correction for blood matrix effect on determination of lead concentration and isotope ratio by ICP-MS].

The research studied the influence of matrix effect on the determination of lead concentration and isotope ratio through simulating blood matrix, and its correction by common analyte internal standardization (CAIS) method. The experiment results showed that CAIS method was suitable for the multi-element-matrix. The relative errors between the determined and the true concentration values are 20% (without correction), 8% (by conventional internal reference correction) and 2% (by CAIS correction), respectively.

[Determination of fifty-five elements in lung carcinomatous tissues and their pericarcinomatous tissues by atomic spectrometry].

A method for determining 55 elements in human lung tissue was developed. Mixed acid (HNO3:HCl04) was added into samples, which were digested at room temperature over night, then heated at 180 degrees C. Arsenic and selenium in lung tissue were determined by hydride generation atomic fluorescence spectrometry (HG-AFS), potassium, sodium, calcium and magnesium were determined by atomic absorption spectrometer (AAS), while the rest of forty-eight elements were determined by inductively coupled plasma mass spectrometry (ICP-MS), respectively.

Effects of zinc, copper, and selenium on placental cadmium transport.

The objective of the present study was to evaluate the potential effects of zinc, copper, and selenium on placental cadmium transport. From November 2002 through January 2003, a total of 47 healthy pregnant women from Da-Ye City, Hubei Province in Central China participated in the study. Their age, parity, gestational age, pregnancy history, and lifestyle data were obtained by questionnaire interview.

[Preliminary attempt at the speciation of 25-elements in the Chinese medicinal herbs].

Objective: To make an attempt at the multi-element speciation in the Chinese medicinal herbs by determining the concentrations of 25 elements in different extraction solutions.

Method: Firstly, five Chinese medicinal herbs (Buddleja officinalis, Dictamnus dasycarpus, Myristica fragrans, Albizia judibrissin and Inula japonica) from the same region of China were treated to obtain water-soluble phase, lipid-soluble phase and non-soluble phase by water extraction, organic solvent extraction and acid digestion, respectively. Secondly, Phytolacca acinosa, a Chinese medicinal herb collected from 9 regions of China, was extracted by 0% EtOH, 50% EtOH, 75% EtOH, 95% EtOH, respectively, referring the Chinese Pharmacopoeia.

Effect of environmental exposure to cadmium on pregnancy outcome and fetal growth: a study on healthy pregnant women in China.

The objective of the present study was to evaluate the potential effect of environmental exposure to cadmium on pregnancy outcome and fetal growth. Normal pregnant women were selected from Da-ye city of Hubei province, a cadmium-polluted area, from November 2002 through January 2003. Whole blood of pregnant women, cord blood, and placenta were collected and cadmium levels were determined by inductively coupled plasma emission mass spectroscopy.