ABSTRACT
Objective To establish an evaluation method of uncertainty for the determination of lead in ambient air PM2.5 by inductively coupled plasma mass spectrometry (ICP-MS). Methods According to HJ657-2013 “Determination of Lead and Other Metal Elements in Air and Exhaust Particulates by Inductively Coupled Plasma Mass Spectrometry”, the concentration of lead in ambient air PM2.5 was determined. A mathematical model was established to analyze the source of uncertainty and to calculate each component of uncertainty. The components were combined into the standard uncertainty, and the relative expanded uncertainty was finally obtained. Results The expanded uncertainty of lead in ambient air PM2.5 was 0.16 ng/m3, and the measurement result of lead was (1.75±0.16)ng/m3. Conclusion The main source of uncertainty of this method comes from the relative standard uncertainty introduced by sample pretreatment.
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In order to meet the needs of detection of poisoning-inducing pesticides occurring in poisoning emergency events, this article introduces and discusses the characteristics, scope of application, and advantages and disadvantages of two types of detection technologies: laboratory detection and on-site rapid detection. The sample pre-processing technology suitable for on-site detection is also elaborated.
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Objective To investigate the nutrient contents of various grains in Hubei Province, and to provide a scientific basis for a balanced diet. Methods Various grains (except potatoes and beans) on the market in Hubei Province were collected. The samples were prepared by peeling and milling, or directly milling, and the nutrient contents were determined according to the national standard methods. With reference to the American nutrient profiling model, protein, dietary fiber, vitamin C, vitamin A, vitamin E, potassium, magnesium, iron and calcium, the nine nutrients were selected as recommended nutrients, and sodium, added sugars and fat were restricted nutrients. On the basis of 100 g for calculation, a nutrient-rich food model (Nutrient-rich foods, NRF9.3) was established and applied to evaluate the grains. Results The evaluation results showed that wheat and buckwheat grains contained a higher recommended nutrient content than restricted nutrient content, and had higher nutritional value. Among them, quinoa (black) had the highest NRF index of 102.4, indicating the most nutritional value. After peeling, the loss rate of nutrient value (NRF9.3 index) of various grains was 38.73% to 65.00%. Conclusion It is recommended that people should try to choose whole grains when purchasing grain products.
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In pace with the progressing and strengthening of administration requirement in standardization, biosafety, and third party accreditation for medical laboratories, internal and external environment itself are becoming important elements for total quality control. Laboratory management starts at planning and design. Making the six conceptions (normalization, safety, practicability, convenience, environment-friendliness, and good-looking) as the forerunners, taking more attention to and perfecting most of the details in the phase of planning and designing of a medical laboratory are therefore offered. The aims of informatization, automation, intellectualization, and hommization would be materialized through normatively partitioning clean, buffer and polluted areas, reasonably arranging the passageways of staff, stuff, air and information, and centrally laying out the electric, water, gases, air-condition, and monitoring, which would lay the good foundation for afterwards use and management of the laboratory.