linq中2个集合取交集

  var trigger_item = "HQ_005,HQ_006,HQ_008,HQ_009";
            var list = trigger_item.Split(',');

            var contract_formula = base.ContractFormulaDb.GetList(a => a.proj_id == proj_id).OrderBy(a => a.s_num).ToList();
            if (!trigger_item.IsNullOrEmpty())
            {
    
    
                contract_formula = contract_formula.Where(a => a.TriggerItem.Split(',').Intersect(list).Any()).OrderBy(a => a.s_num).ToList();
            }