Gonzalez Helena, Jacobson Carl-Eric, Wennberg Ann-Marie, Larkö Olle, Farbrot Anne
Department of Dermatology and Venereology, Sahlgrenska University Hospital, S-413 45 Göteborg, Sweden.
Anal Chem Insights. 2008 Jan 31;3:1-7. doi: 10.4137/aci.s396.
Benzophenone-3 (BZ-3) is a common ultraviolet (UV) absorbing compound in sunscreens. It is the most bioavailable species of all UV-absorbing compounds after topical application and can be found in plasma and urine.
The aim of this study was to develop a reverse-phase high performance liquid chromatography (HPLC) method for determining the amounts BZ-3 and its metabolite 2,4-dihydroxybenzophenone (DHB) in human urine. The method had to be suitable for handling a large number of samples. It also had to be rapid and simple, but still sensitive, accurate and reproducible. The assay was applied to study the urinary excretion pattern after repeated whole-body applications of a commercial sunscreen, containing 4% BZ-3, to 25 healthy volunteers.
Each sample was analyzed with regard to both conjugated/non-conjugated BZ-3 and conjugated/non-conjugated DHB, since both BZ-3 and DHB are extensively conjugated in the body. Solid-phase extraction (SPE) with C8 columns was followed by reverse-phase HPLC. For separation a Genesis C18 column was used with an acethonitrile-water mobile phase and the UV-detector was set at 287 nm.
The assay was linear r(2) > 0.99, with detection limits for BZ-3 and DHB of 0.01 micromol L(-1) and 0.16 micromol L(-1) respectively. Relative standard deviation (RSD) was less than 10% for BZ-3 and less than 13% for DHB. The excretion pattern varied among the human volunteers; we discerned different patterns among the individuals.
The reverse-phase HPLC assay and extraction procedures developed are suitable for use when a large number of samples need to be analyzed and the method fulfilled our objectives. The differences in excretion pattern may be due to differences in enzyme activity but further studies, especially about genetic polymorphism, need to be performed to verify this finding.
二苯甲酮 - 3（BZ - 3）是防晒剂中一种常见的紫外线吸收化合物。局部应用后，它是所有紫外线吸收化合物中生物利用度最高的一种，可在血浆和尿液中检测到。
本研究旨在开发一种反相高效液相色谱（HPLC）方法，用于测定人尿液中BZ - 3及其代谢物2,4 - 二羟基二苯甲酮（DHB）的含量。该方法必须适用于处理大量样本。它还必须快速、简单，但仍需灵敏、准确且可重复。该测定方法用于研究25名健康志愿者全身反复涂抹含4%BZ - 3的市售防晒霜后的尿排泄模式。
由于BZ - 3和DHB在体内都会广泛结合，因此每个样本都针对结合型/非结合型BZ - 3和结合型/非结合型DHB进行分析。采用C8柱进行固相萃取（SPE），然后进行反相HPLC分析。分离使用Genesis C18柱，以乙腈 - 水为流动相，紫外检测器设置在287nm。
该测定方法线性关系良好，r(2) > 0.99，BZ - 3和DHB的检测限分别为0.01 μmol L(-1)和0.16 μmol L(-1)。BZ - 3的相对标准偏差（RSD）小于10%，DHB的相对标准偏差小于13%。人类志愿者的排泄模式各不相同；我们在个体之间发现了不同的模式。
所开发的反相HPLC测定方法和萃取程序适用于需要分析大量样本的情况，该方法达到了我们的目标。排泄模式的差异可能是由于酶活性的差异，但需要进行进一步研究，特别是关于基因多态性的研究，以验证这一发现。
