The distribution coefficients of lipopeptide biosurfactant in four different commercially available organic solvents and water were determined by HPLC. A method with a high recovery of 92.1 % for isolation of the lipopeptide in a surfactant/polymer mixture in aqueous solutions was established by using the combined means of acid extraction, alkaline conversion and acid reextraction. The results showed that the lipopeptide distribution coefficients range from 0.010 to 61 at different pH values in different organic solvents, which is an indicator for optimizing the process of separation of lipopeptide biosurfactant in surfactant/ polymer mixtures in aqueous solutions. The proposed separation method was used to determine the lipopeptide biosurfactant concentration in production fluids of the Daqing oil field. The concentrations were 6.57 lg/L and 4.56 lg/L.

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Significance: The light dose in photodynamic therapy (PDT) has a considerable influence on its treatment effect, and irradiance uniformity is an issue of much concern for researchers. However, achieving intelligent and personalized dosimetry adjustments remains a challenge for current PDT instruments.Aim: To meet the requirements of intelligent and personalized dosimetry adjustments for the light dose on an irregular surface, a new PDT device with its optimal control method is proposed.Approach: This research introduces a new PDT device that includes a 3D scanner, a light-emitting diode (LED) array, and a computer. The 3D scanner is proposed to generate the point cloud of the lesion and the LED array light source, and obtain the relative position and rotation parameters between them. Then, an image segmentation algorithm is used to segment the lesion point cloud into several cluster regions. Last, the current of each LED unit is adjusted separately to achieve the expected irradiance on each cluster.Results: Compared with the general light source, the optimized light source increases the effective irradiance area by 9% to 15% and improves its uniformity by ∼9% on a human port-wine stain head model. Conclusions:The device and its optimal method may be used for optimizing the light dosimetry to realize intelligent and personalized treatment.