The methods for gypsum content determination in soils are summarized and their applicability discussed. Special attention is given to the critical step of sample preparation, stressing the elimination of the oven heating at temperatures surpassing 40°C. Wet methods are unsuitable for soils rich in gypsum or containing other sulfates. Instead, oven‐based methods playing on the mass variations due to the release of constitutional water of gypsum are preferable. Under laboratory settings, we recommend two existing methods: one directly measuring the loss of mass on heating and the other exploiting the gypsum–bassanite phase change under controlled conditions. Both reflectance and X‐ray fluorescence (XRF) provide nondestructive methods for quick gypsum appraisal, and combining both methods increases the accuracy. The results are easily calibrated with gravimetric methods.

中文翻译：

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土壤石膏测定

总结了测定土壤中石膏含量的方法，并讨论了其适用性。特别注意样品制备的关键步骤，强调消除温度超过40°C的烤箱加热。湿法不适用于富含石膏或含有其他硫酸盐的土壤。取而代之的是，最好采用基于烤箱的方法来处理由于石膏中构成水的释放而引起的质量变化。在实验室环境下，我们推荐两种现有方法：一种直接测量加热时的质量损失，另一种利用可控条件下的石膏-玄武岩相变。反射率和X射线荧光（XRF）都提供了用于快速评估石膏的非破坏性方法，并且将这两种方法结合使用可提高准确性。