What does the term 'endotoxins' refer to in water analysis?

Endotoxins specifically refer to toxic components that are found within the cell membrane of Gram-negative bacteria. These substances consist mainly of lipopolysaccharides (LPS), which are significant in terms of water quality assessment because they can lead to harmful effects on human health and aquatic life when present in water supplies. When Gram-negative bacteria die, they release these endotoxins into the environment, which can have various negative effects, including fever and inflammatory responses in humans.

Understanding the nature of endotoxins is crucial for water analysis, particularly in treating wastewater and ensuring drinking water quality, as contamination can indicate the presence of pathogenic bacteria. Other options, such as components of Gram-positive bacteria or substances described as harmless particles, do not accurately define endotoxins and are not relevant in this context.