Towards Iodine and Lead Determination in Field Settings

Field testing has several advantages including the elimination of sample
transportation time and cost, opportunity to educate participants, and rapid determination
of remedial action on site. Iodine, an essential micronutrient that is required to be
determined at the population level, lacks a field test. The Sandell-Kolthoff urinary iodine
reaction is the gold-standard laboratory test whose pretreatment step is not field-friendly.
To aid the development of a field test, I completed an interference study, identifying most
significant interference from urobilin.
Lead is a neurotoxin with major exposure pathways through dust and water but
lacks sensitive field screening tests for these matrices. The portable X-ray fluorescence
analyzer (XRF) is currently used in the health department gold-standard lead risk
assessment (LRA) for determining lead in paint. I have built upon previous work from
our lab for deploying the XRF as a screening tool for lead in dust and water, with
increased sensitivity and robustness.

现场检测具备多项核心优势：可省去样本运输的时间与成本，能够对受试对象开展科普宣教，还可在现场快速制定针对性补救措施。碘作为人群水平监测必需的微量营养素，目前尚无适配的现场检测方法。桑德尔-科尔特夫尿碘反应法（Sandell-Kolthoff urinary iodine reaction）是实验室检测尿碘的金标准，但该方法的前处理流程并不适配现场检测场景。为推动现场检测方法的开发，本研究开展了干扰物排查实验，确定尿胆原（urobilin）为最主要的干扰因素。
铅是一种神经毒素，其主要暴露途径为粉尘与饮水，但目前针对这两类基质尚无高灵敏度的现场筛查手段。便携式X射线荧光分析仪（portable X-ray fluorescence analyzer, XRF）目前已被卫生部门应用于涂料中铅含量检测的金标准铅风险评估（lead risk assessment, LRA）流程。本研究基于本实验室前期工作成果，将XRF开发为适用于粉尘与水体中铅筛查的检测工具，并提升了其检测灵敏度与鲁棒性。