Bannon D I, Murashchik C, Zapf C R, Farfel M R, Chisolm J J
Kennedy Krieger Institute, Trace Metals Laboratory, Baltimore, MD 21213.
Clin Chem. 1994 Sep;40(9):1730-4.
Now that the level of concern for a toxic blood lead concentration is 0.482 mumol/L (10 micrograms/dL), laboratories must meet new requirements to shorten analysis times and increase accuracy and precision of blood lead determinations. We used a matrix-matching method to estimate the lead concentration in blood by graphite furnace atomic absorption spectroscopy (GFAAS). For CDC proficiency samples and the NIST-Certified Blood Reference standard, the performance of this method compared favorably with that of previously published GFAAS methods and of the anodic stripping voltammetric method routinely used in our laboratory. At lead concentrations of 0.242 mumol/L (5.01 micrograms/dL) and 1.478 mumol/L (30.63 micrograms/dL), within-run CVs were 2.78% and 0.68%, respectively; between-run CVs were 4.9% and 1.35%. In 52 study samples with lead content ranging from 0.097 to 3.812 mumol/L (2 to 79 micrograms/dL), 87% of results by the matrix-modified method were within 0.048 mumol/L (1 microgram/dL) of consensus values.
鉴于对血液铅中毒浓度的关注水平为0.482微摩尔/升（10微克/分升），实验室必须满足新的要求，以缩短分析时间，并提高血铅测定的准确性和精密度。我们采用基体匹配法，通过石墨炉原子吸收光谱法（GFAAS）来估算血液中的铅浓度。对于美国疾病控制与预防中心（CDC）的能力验证样本以及美国国家标准与技术研究院（NIST）认证的血液参考标准品，该方法的性能与先前发表的GFAAS方法以及我们实验室常规使用的阳极溶出伏安法相比更具优势。在铅浓度为0.242微摩尔/升（5.01微克/分升）和1.478微摩尔/升（30.63微克/分升）时，批内变异系数（CV）分别为2.78%和0.68%；批间变异系数分别为4.9%和1.35%。在52个铅含量范围为0.097至3.812微摩尔/升（2至79微克/分升）的研究样本中，基体改进法所得结果的87%与共识值的偏差在0.048微摩尔/升（1微克/分升）以内。
